PHILADELPHIA -- Injuries are always the first thing anyone mentions when discussing Philadelphia Eagles quarterback Sam Bradford.

That was the case in the new "Quarterback Tiers” project (Insider) from ESPN.com football writer Mike Sando. Sando is a smart, careful analyst in his own right. For this project, though, he polled 35 NFL insiders – head coaches, coordinators, general managers – about each of the league’s starting quarterbacks. Players were placed in one of four tiers, with Super Bowl-caliber stars like Aaron Rodgers and Tom Brady in the first tier and non-contenders in the fourth.

Bradford landed in the third tier – quarterbacks who are “good enough to start but need lots of support, making it tougher to contend at the highest level.” Bradford finished tied with Minnesota’s Teddy Bridgewater for 23rd among NFL starting quarterbacks, largely because of his injury history.

Remember: Bradford started the first seven games of the 2013 season before tearing his anterior cruciate ligament. He tore the ligament again last summer and missed the entire 2014 season.

In discussing Bradford, though, Sando unearthed some interesting insights into his abilities and his liabilities.

"I thought he was a 2 [second tier] coming out [in the 2010 draft] because I did not see the big arm," one head coach told Sando. "No one could tell from his pro day because [agent] Tom Condon wouldn't let him throw any deep comebacks. He has the intangibles, but you have to give him a 3 or 4 just because he is always hurt. Frankly, you probably want him to be your backup, just for his availability."

One defensive coordinator told Sando that Bradford will be better in Chip Kelly’s offense because of the Eagles’ use of play-action to buy him time. Another head coach said he “loved” Bradford coming out of college, but again cited his injuries as the reason he rated him only a third-tier quarterback.

Interestingly, Nick Foles finished just ahead of Bradford at No. 22 overall. Foles was also in the third tier, however. The experts gave some insight into why Kelly likely soured on Foles, deciding to trade him to St. Louis and take his chances with Bradford.

“He is a little stiff in the pocket,” one personnel director told Sando. “I don't think he has great arm strength. He has pretty good accuracy. I don't know that he sees everything."

A coach said he watched Foles’ performance last season against Jacksonville and that Foles had trouble seeing wide-open receivers downfield.

That helps solve one mystery: Kelly’s disillusionment with Foles. But that mystery has been replaced by the mystery of Bradford.