Streit, the Islanders' team captain, has 65 goals and 288 points in 491 regular-season NHL games, and is a sharp, left-handed shot from the blue line that is much-needed as Philadelphia reshapes its roster.
Streit, though, is scheduled to become an unrestricted free agent on July 5, meaning he can sign anywhere. But the Flyers now own his rights until then, and can negotiate a new deal with him exclusively until that time.
The 35-year-old Streit joined the Islanders as a free agent in 2008, led the team in scoring his first season with 56 points and was an All-Star. Should he stay with Philadelphia, he would bolster the Flyers' backline, which was decimated by injuries last season and was a prime reason the club did not make the postseason.
"Mark is a player we would have had interest in on July 5th," Flyers general manager Paul Holmgren told the team's website. "We now have exclusive negotiating rights and we are hopeful that we can get an agreement in place prior to him becoming an unrestricted free agent."
Streit made $4.1 million this season in New York, and had six goals and 27 points. Though he has impressive scoring totals for a defenseman, Streit's value - and his reputation around the league - is more for being a workhorse and an anchor on the backline. This season, as the Islanders secured the No. 8 seed in the Eastern Conference, Streit played in all 48 games. He also had three goals and five points in a six-game, first-round loss to the Pittsburgh Penguins.
Streit also played for Switzerland's Olympic team in 2006 and 2010.
Harper had 20 goals and 21 assists over parts of four seasons with the AHL's Phantoms.