College football Top 25: Each team's biggest reason for optimism

We've already looked at the biggest concerns facing each of college football's Top 25 teams. So it's only fair we consider the teams' biggest reason for optimism heading into the 2019 season.

Trevor Lawrence. Justyn Ross. Travis Etienne. Tee Higgins. Take your pick. The offense is so stacked with elite, experienced talent that it's hard to envision Clemson being anything other than a scoring machine in 2019. OK, sure, Hunter Renfrow won't be back (we'll believe it when we see it!), but across the board, this looks like as deep and talented an offense as there is in the country, and it's more than capable of taking some of the stress off a defense that could still be finding its footing early in the season. -- David M. Hale

You might not like the hiring of Steve Sarkisian as offensive coordinator. A lot of Alabama fans seem to feel that way. But given all the returning talent on that side of the ball, does it really matter? Tua Tagovailoa is back. So are his top four receivers:Jerry Jeudy, DeVonta Smith, Henry Ruggs III and Jaylen Waddle. Damien Harris and Josh Jacobs are gone at running back, but that could just mean it's Najee Harris' time to finally shine. With so much skill on offense, it's going to be hard for Sarkisian to do anything other than put up points. -- Alex Scarborough

There are a few key seniors moving on, but don't be surprised if the defense actually improves next season. Only Deandre Baker is leaving a secondary that has a couple of nice anchors in J.R. Reed and Richard LeCounte. Meanwhile, Jordan Davis and Julian Rochester are a couple of nice cornerstones on the line. Monty Rice might be the only sure thing returning at linebacker, but the addition of the No. 2 overall prospect in the 2019 class, Nolan Smith, could give coach Kirby Smart a plug-and-play pass-rusher. -- Scarborough

Ryan Day's offense was tough for most defenses to stop, but the Ohio State defense had issues throughout the season. While Ohio State is losing defensive end Nick Bosa and defensive tackle Dre'Mont Jones, most of the defense is returning next season. Bosa didn't play much of last season anyway, and Chase Young showed a ton of promise in his place. Now, with new defensive coaches Greg Mattison and Al Washington, who came over from Michigan, along with Jeff Hafley, who is coming from the San Francisco 49ers, the defense should be in the top tier in 2019. -- Tom VanHaaren

Book's struggles against Clemson in the CFP semifinal shouldn't overshadow all the great work he did in 2018. A full offseason as the starter under coordinator Chip Long should set up Book for an even more productive season. Book will have wide receiver Chase Claypool, tight end Cole Kmet and others at his disposal, playing behind an offensive line that returns three starters but must replace standout center Sam Mustipher. -- Adam Rittenberg

Hurts, the transfer QB from Alabama, will potentially be surrounded by three preseason All-Americans in wide receiver CeeDee Lamb, tight end Grant Calcaterra and center Creed Humphrey. The Sooners do have to retool elsewhere, particularly along the offensive line, where four starters are gone. Still, with Hurts on board behind center, the front line of the offense will be about as dynamic as it gets in college football. -- Jake Trotter

By the time the 2018 season ended, the Gators looked like they had a legitimate offense going, making improvements in every category -- especially quarterback. Feleipe Franks clearly got better as the season went on, and his triumphant performance in the Chick-fil-A Bowl against Michigan was the exclamation point. Franks goes into the spring sure to face competition from Emory Jones for the starting job. But it's Franks' development and the strides Dan Mullen made with this group in Year 1 that are the reasons for optimism. -- Andrea Adelson

In Sam Ehlinger, the Longhorns have their first championship-caliber quarterback in close to a decade. After a flashy but inconsistent true freshman season, Ehlinger emerged into one of the top quarterbacks in college football as a sophomore in 2018. Uneven quarterback play had been holding Texas back in recent years. Now that the Longhorns have a standout in Ehlinger, they could be finally ready to contend for the College Football Playoff. -- Trotter

The Aggies return most of their key offensive pieces in 2019: quarterback Kellen Mond, all of their starting receivers and both starting offensive tackles. There are some important pieces departing, namely running back Trayveon Williams, center Erik McCoyand tight end Jace Sternberger, but with Mond entering his third year as the starting quarterback and making significant progress in 2018 under coach Jimbo Fisher, the offense should be able to take an even bigger step in the coming season. -- Sam Khan Jr.

For once, the Tigers don't have a huge question mark at quarterback. With Burrow turning in a solid 2018 season after joining the program as a grad transfer from Ohio State, he'll have a full offseason -- including spring drills -- to further develop in Steve Ensminger's offense. None of the Tigers' 2018 receivers were seniors, so Burrow will benefit from the experience returning. The passing game could take another step forward, which is important for LSU if it's going to contend for the College Football Playoff. -- Khan

As much as Michigan is losing on defense, it is returning almost the entire starting offense from 2018. Running back Karan Higdon, tight end Zach Gentry, offensive linemen Jon Runyan and Juwann Bushell-Beatty, along with wide receiver Grant Perry are the only offensive losses. Quarterback Shea Patterson and receivers Nico Collins, Donovan Peoples-Jones and Tarik Black are all back, and they will have a new offensive coordinator to utilize their strengths. Michigan hired Josh Gattis from Alabama to lead the offense, and Gattis has said he plans to utilize the personnel and get its speed in space to modernize the Wolverines' attack. That statement alone has Michigan fans excited about what the product on the field will look like in 2019. -- VanHaaren

Quarterback Justin Herbert had a choice: Enter the NFL draft, where he would become a millionaire overnight and be in the mix to be the first player selected, or return to school and play a final season with the Ducks. He chose the latter, of course, which is a major factor in the high expectations for Oregon in 2019. Add in the conference's best recruiting class, and there's a lot to be excited about in Eugene. -- Kyle Bonagura

Over the past four seasons, only Stanford (27) has more Pac-12 victories than the Cougars. That speaks more to what Mike Leach has accomplished than anything: The Cougars' success is sustainable. That has always been the issue in Pullman. So long as Leach is around, Wazzu figures to remain a player in the Pac-12 North. Get used to hearing the name Max Borghi. After an encouraging freshman season, the running back has a chance for a breakout sophomore campaign. -- Bonagura

Nobody knows when or if McKenzie Milton will return after sustaining a devastating knee and leg injury in the regular-season finale, but the Knights now have some options at the position headed into the spring. Brandon Wimbush's transfer from Notre Dame provides an instant upgrade at the position, whether or not he ultimately wins the starting job over Darriel Mack Jr. Wimbush provides game experience, veteran leadership and much more depth at a position that could use it. He's the most high-profile transfer UCF has ever gotten and appears to be a good fit for the Knights' offense. -- Adelson

The Orange return a ton of key starters for 2019, but the real excitement comes from two transfers who just got a taste of action. Running back Abdul Adams, an Oklahoma transfer, and receiver Trishton Jackson, who came from Michigan State, should add some huge playmaking threats to an already explosive offense. In Syracuse's bowl victory over West Virginia, the duo got its first taste of action in Orange, combining for three touchdowns. Syracuse fans can't wait to see what they might do over a full season. -- Hale

Jake Browning's Washington career will be celebrated for years because of what the Huskies accomplished with him as their quarterback, but ever since Jacob Eason transferred to Washington from Georgia last year, there has been buzz about 2019. He'll still need to beat out a talented group that includes another Jacob (Sirmon) and another Jake (Haener), but Eason, a local product who won the Gatorade National Player of the Year in 2015, figures to be the favorite. -- Bonagura

The Nittany Lions appear to possess the talent and depth to reclaim their position as Linebacker U. Micah Parsons, a top-10 recruit nationally a year ago, flashed stardom as a true freshman and figures to emerge as an All-America-caliber defender with a more steady role in the defense. Newcomer Brandon Smith arrives with the same kind of potential to complement Penn State's mix of depth and experience, featuring the likes of senior Cam Brown and sophomore Jesse Luketa. -- Mitch Sherman

On the day of the College Football Playoff National Championship, Utah quietly announced that DE Bradlee Anae, DT Leki Fotu, RB Zack Moss and CB Julian Blackmon would all return for their senior seasons after weighing early departure for the NFL draft. All four received All-Pac-12 honors last season, and their return makes the Utes the clear favorite in the Pac-12 South, if not the entire conference. -- Bonagura

Northwestern has defied metrics in going 36-17 since 2015 despite ranking 123rd in yards per play and 121st in percentage of plays of 10 yards or longer. Quarterback Hunter Johnson should inject more life into the unit as the highest-rated signal-caller Northwestern has ever had. The Clemson transfer boasts an excellent arm and more elusiveness than predecessor Clayton Thorson. Northwestern should get more from talented young receivers like JJ Jefferson, Ramaud Chiaokhiao-Bowman and incoming freshman Genson Hooper-Price. -- Rittenberg

The easy answer is quarterback Brock Purdy, who stabilized the Cyclones as a true freshman, then led them to a second-consecutive eight-win season. But we're looking across the line at the defensive front, where Ray Lima and JaQuan Bailey return as senior anchors. The defensive line in 2019 should be better than the group that led the Big 12 and ranked ninth nationally last season in allowing 3.26 yards per rush. -- Sherman

Running back Jonathan Taylor is still on the team. Taylor led the Big Ten in rushing yards this past season with 2,194 yards. Beside Taylor, the coaches are also bringing in the top-ranked pocket-passing quarterback in the 2019 class in Graham Mertz. The passing game did not match the run game for Wisconsin last season, so if Mertz can push starter Alex Hornibrook, or take the starting spot, it could make the offense more than a one-dimensional unit with Taylor running the ball. -- VanHaaren

Bryant's arrival as a grad transfer quarterback from Clemson rates as a coup for Mizzou and its cast of returning offensive talent. And that's not to mention QB Shawn Robinson, who will sit in 2019 upon moving from TCU. Bryant provides immediate credibility as a Manning Award finalist in 2017, former understudy to Deshaun Watson and offensive leader of Clemson's College Football Playoff team of two seasons ago. He figures to make a smooth transition in replacing Drew Lock. -- Sherman

No one knows whether the offense will improve next season, but the defense should stay right on track thanks to the somewhat surprising return of NFL prospects Derrick Brown and Marlon Davidson. With Nick Coe also back, the Tigers' defensive line should once again be formidable. Safeties Daniel Thomas and Jeremiah Dinson return as well. The big question mark is at linebacker, however, with three starters gone from last season's squad. -- Scarborough

He wears No. 2, stands 6-foot-2 and carries a heavy burden. The play of quarterback Adrian Martinez as a true freshman last season is not the sole source of expectations that the Cornhuskers will show dramatic improvement after a 4-8 finish in coach Scott Frost's debut season -- but it's the top factor by a big margin. Martinez ranked 12th nationally in total offense last season and rated arguably as the most impactful rookie QB nationally this side of Trevor Lawrence. -- Sherman

Hopkins last fall became the first Army quarterback to eclipse 1,000 passing yards since 2007, while leading the Black Knights in rushing yards (1,017) and rushing touchdowns (17). Coach Jeff Monken can continue to broaden the passing game with Hopkins as he returns for his senior season. The offensive line was a major strength in 2018, and if the Knights can replace center Bryce Holland and left tackle Austin Schuffert, they will continue to pile up points and possession time. -- Rittenberg