Finally, what we all kinda, sorta knew is official: Sam Bradford, who has a concussion and a shoulder injury of some degree, is out for Sunday's game against Tampa Bay. Mark Sanchez is in. Let the scrutiny begin.

Along with the change at quarterback, the Eagles also head into Sunday's very important game minus running back Ryan Mathews, who has a concussion/groin injury and who has not practiced this week. In theory, DeMarco Murray will get a large workload with Darren Sproles and Kenjon Barner mixing in.

Left tackle Jason Peters is questionable after seeing limited practice time, so it sounds like a morning-of decision for him, just as it was last week. If Peters can't go, the Eagles will start Lane Johnson at left tackle and Dennis Kelly at right tackle and, well, away we go.

Sanchez is the biggest news, but it's not really news since he's taken the role of starter all week in training. Sanchez knows the offense and the players have trust in him and the coaches believe in him and he's won football games for this team. He's a good quarterback. He's an even better one when he tamps down on the giveaways -- in the two games without interceptions last season, against Carolina and at Dallas, Sanchez compiled passer ratings of 102.5 and 102.2, respectively, his best numbers of the season in the games that were both wins -- but that's a narrative that has been discussed at length this week and there is really no new light to shed there.

What is worth discussing is how the offensive structure changes, even if ever so slightly, with Sanchez on the field. Do the Eagles move him around to take advantage of his legs? Do they dial up a read-option play or two with the actual consideration that Sanchez will keep the football and move the sticks on some quarterback keepers? Rolling the pocket and helping the offensive line is a consideration against a defense that likes to bring the blitz. You can bet on that, by the way: Tampa Bay is coming after Sanchez. The Bucs are going to blitz.

"You have to be ready for anything with them," center Jason Kelce said during the week. "They're aggressive. They get up the field. They're fast and they're good. We're going to have our hands full."

There are many thoughts on this game. Let's discuss ...

• How much will tight ends Brent Celek and Zach Ertz be involved in the passing game? Sanchez likes to attack the middle of the field, and Ertz did have 15 receptions in the game at Washington last year with Sanchez as the starting quarterback, but it isn't like Ertz' numbers jumped dramatically when Sanchez replaced Nick Foles in Houston on Nov. 2 and stayed at quarterback the rest of the season. In fact, other than that Washington game, Ertz had no more than four receptions in a single game -- he had four against Green Bay, Tennessee and at New York.

• No. 1 draft pick Nelson Agholor has 11 catches in the six games he's played this season. Mark down this moment. Let's see how he does for the remaining seven games. I get the sense that he's going to have an increase in targets the rest of the way. The Eagles really want to get him going.

• A scouting report on Mike Evans, the 6-5 Tampa Bay wide receiver who has been targeted 85 times in the Bucs' nine games this season: "Big, goes up and gets it, huge body, uses it really well," cornerback Byron Maxwell said. "He's tough. He can also run. We have to be on him and make sure he doesn't get loose on us. It's a group thing."

• I've seen and heard so much about the Bucs this week from various people -- coaches, players, members of the media in Philadelphia and in Tampa Bay -- and here is what I generalize about Tampa Bay's defense: Very fast, likes to blitz, plays the run on the way to the pass, can be beaten on play-action passing, vulnerable in the deep secondary and led by tackle Gerald McCoy and linebackers Lavonte David and Kwon Alexander. Don't know what that means, really. We'll see how much of it comes true on Sunday.

• Ed Reynolds has his chance on the active roster with Jerome Couplin on Injured Reserve for the season. Reynolds seems to have made nice progress since last year. He opened eyes in the preseason with some big plays. Smart kid, knows the system and has to show he can run sideline to sideline in coverage to make it in the NFL.

• Some Tampa Bay injuries to watch leading into Sunday's kickoff. The Bucs will be without defensive end George Johnson, who has been ruled out. Defensive end Josh Shirley is listed as doubtful. Another defensive end, Jacquies Smith, is questionable with an ankle injury. Wide receiver Vincent Jackson is questionable with a knee injury, but he could very well play. Tight end Austin Seferian-Jenkins hasn't been cleared for full contact with a shoulder injury and is questionable. Offensive guard Ali Marpet is questionable with an ankle injury and center Evan Smith is questionable with a knee injury.

• The Philadelphia run defense started the year absolutely sizzling and the numbers haven't been as impressive recently. Tampa Bay wants to establish the ground game with Doug Martin, so the Eagles have to get quarterback Jameis Winston in third-and-long situations by stopping the run on first and second downs. Huge game for the three-man front, yes, but equally huge for the linebackers inside. They have to play downhill and tackle well. Bill Davis is going to give Winston a lot of different looks, which will be a lot more effective if the third downs are third-and-long downs.