Chip Kelly knows risk with Sam Bradford

PHILADELPHIA -- Let's start with a technicality. Sam Bradford did not tear the same anterior cruciate ligament twice.

Bradford tore his left ACL in November 2014. When Dr. James Andrews performed surgery on Bradford's knee, he built a new ACL out of tissue taken from elsewhere in Bradford's body. So it was a totally different ACL that tore Aug. 23 during a preseason game. And it is a third ACL, built from new tissue, that is helping to stabilize Bradford's knee as he returns to training camp on Sunday.

Why point that out? Only to underscore the medical details surrounding the risk Philadelphia Eagles coach Chip Kelly decided to take by trading Nick Foles for Bradford. It is a risk that some NFL teams would not take, a point made last week by ESPN's Louis Riddick. Riddick, who worked for the Eagles as a personnel executive from 2008 to 2013, told 97.5 The Fanatic that he wouldn't have traded for Bradford.

"Would I have traded for someone like that?" Riddick said. "My first inclination would be to say 'No.' I'm very much one of those guys who believes that someone who has an injury history before will have an injury history after. It's very hard to shake it.

"Especially when you're talking about that position and the nature of his injury, it's just hard to shake that history."

Kelly had a different view. He said the Eagles studied the history of players returning from two ACL tears. The study showed that there was a "10 to 12 percent chance" of re-injury.

"Everybody gets hurt in this game," Kelly said. "I don't know any quarterback that hasn't missed time. ... Our research in terms of dealing with guys with two ACLs, there's a 10 to 12 percent chance of re-injury. That's an 88 to 90 percent chance that they're going to be successful."

Kelly took those odds because he simply didn't see another way to upgrade the quarterback position. After two seasons in which Michael Vick and Foles missed games with three different injuries, Kelly felt it was time to try something new.

He looked around and saw that elite quarterbacks only occasionally changed teams. And when they did, it was usually because they were injured. San Diego chose not to re-sign Drew Brees after he badly injured his shoulder at the end of the 2005 season. The Chargers had taken Philip Rivers in the 2004 draft and felt he was ready to be their No. 1 quarterback. Brees signed with the New Orleans Saints and has been one of the NFL's premier quarterbacks ever since.

After Peyton Manning missed the 2011 season with a neck injury, the Indianapolis Colts were in position to select Andrew Luck in the 2012 draft. Manning was signed by the Denver Broncos. He hasn't missed a start in the three seasons since, and took the Broncos to the Super Bowl in the 2013 season.

"We looked at everything," Kelly said. "We knew we weren't going to pick No. 1 or No. 2 [in the draft]. If you're not going to pick 1 or 2, how do you go get a quarterback? Peyton Manning switched teams because of injury. Drew Brees switched teams because of injury. We went down that route."

No one has to tell Kelly that there's a risk involved with Bradford. He simply felt that risk was preferable to the risk of trying to take the Eagles to the next level with Foles as his starting quarterback.

"We know it's a risk, but it's a risk we're willing to take," Kelly said.