PHILADELPHIA -- Once you’ve won a Super Bowl with Brad Johnson as your starting quarterback, your opinion on the position carries some weight.

Since Jon Gruden has been preparing to call the Monday Night Football game between the Eagles and the Atlanta Falcons, he has spent a lot of time studying Sam Bradford. And yes, the one-time Eagles offensive coordinator has formed some opinions.

“Remember,” Gruden said last week in a conference call with reporters, “Sam is very comfortable in a no-huddle offense. I remember when he came in here, he was very comfortable in this uptempo, speed style of offense. And he looks at home in Chip Kelly’s system. At least in that Green Bay game -- not many guys go 10-for-10 in Lambeau at any point.”

Bradford completed all 10 of his passes -- three for touchdowns -- in his final preseason appearance in Green Bay. That could be a preview for what’s to come as Bradford runs Kelly’s offense.

“If you get them open, and you give him protection, Bradford is a pinpoint passer,” Gruden said. “The question is can you get them open all the time, and can he stay healthy? Can you protect him as you have throughout the preseason?”

The St. Louis Rams traded Bradford to the Eagles for Nick Foles and a second-round draft choice. Gruden sounds like he would have made that trade from Kelly’s perspective, even though Foles had a great season in 2013.

“Everybody goes back to 27 touchdowns and two interceptions,” Gruden said, citing Foles’ 2013 numbers. “He didn’t play as well the following year and he was hurt two years in a row. Sam’s had injuries, but so has Nick Foles.”

Kelly said it was an opportunity to acquire a potential Super Bow-caliber, franchise quarterback. Listening to Gruden, you get the sense he agrees with that assessment.

“I don’t think many people come across the road that can throw the ball like Sam Bradford. If this kid stays healthy and they can protect him, Kelly’s proven he can get open targets for him. If Same Bradford gets protection, he can shred you real bad. He is a phenomenal passer. He’s just been hurt.”

That is the X factor. Bradford tore the ACL in his left knee twice in 10 months. He had it surgically repaired both times, most recently in August of 2014. Bradford has gotten through OTAs, training camp and two preseason games.

Now the real work begins.

“That’s the only question I have with Bradford,” Gruden said. “Can he stay healthy and play 85 snaps a game for 16 weeks and into the playoffs? Obviously, St. Louis didn’t think so.”

Chip Kelly thinks so. He certainly hopes so.