Despite 50 receivers ranked ahead of him, his attitude is still optimistic.
"That just drives me to go harder each and every day. Let's prove them wrong. That's just experts saying that this guy is better than you. I don't believe what they say," said Mack. "I want to be pretty dominant in the NFL. I just don't want to be a regular wide receiver. I want to be dominant."
Mack gets his passion and drive from his father Daryl, who never saw him play at Temple University. He died of a heart attack in the spring of 2017, just months before his college debut.
One of the last things Mack says he told his father was, "Dad, I'm going to make it to the NFL."
"If he was here right now, I could imagine, he will be running around the house screaming and hugging. He would be so proud right now, and I just want to make him proud because I know he's looking down on me from above," added Mack.
When Mack's father passed away, Mack says he had such a difficult time that he even thought about quitting football. But Temple Football coach Geoff Collins talked him out of it, and so did Mack's mother, Nicole Mack.
They said stick with it, for your dad.
"It was extremely tough. He called me up and said, 'I can't do this no more. I can't do it, it's not the same.' I told him you can do it," said Nicole Mack.
Brendon Mack says he remembers the painful time.
"I kinda lost love of the game, but my teammates and family supported me so much through that time. I started to fall back in love with the game," he said.
Mack says he would love nothing more than to play for the Philadelphia Eagles, who have been among the most interested.
It would be the cherry on top since it's both Mack and his father's favorite team.