How long will Eagles need Mark Sanchez and can he hit his stride in time?

PHILADELPHIA -- Sam Bradford just seemed to be hitting his stride in the Philadelphia Eagles' offense. Now, the team has to wait for Mark Sanchez to hit his.

A week after his best game, the Eagles' 33-27 overtime victory in Dallas, Bradford got off to his best start Sunday against the Miami Dolphins. The Eagles scored 16 points in the first quarter, taking a 16-3 lead.

They wound up losing 20-19. Along the way, they lost Bradford. He sprained his left shoulder and received a concussion on a third-quarter sack by Miami linebacker Chris McCain.

It is unclear how long Bradford will be out. After the game, Sanchez sounded as though he expects to play next Sunday against the Tampa Bay Buccaneers, at least.

Asked about a few awkward handoffs to DeMarco Murray, Sanchez said, "Just different quarterback footwork. I think it's something we will get ironed out this next week in practice."

This is a repeat of last season. In a Nov. 2 game in Houston, Nick Foles was sacked and left the game with a broken collarbone. In this game, Bradford went down with a shoulder injury and a concussion.

Sanchez came into the game against the Houston Texans and led the Eagles to a 31-21 victory. He was the starter when they beat the Dallas Cowboys in Dallas on Thanksgiving Day. The Eagles got to 9-3 with Sanchez as the starter.

They lost their next three games and were eliminated from playoff contention. Sanchez threw four touchdown passes and four interceptions in those three losses.

On Sunday, Sanchez completed 14 of 23 passes for 156 yards. His most critical throw was an interception by Reshad Jones in the end zone, a play that brought back memories of last season.

"I'm not thinking about last year," Eagles head coach Chip Kelly said. "I'm just thinking about today, and it hurt us. We'll work around it, get with him and figure out what's going on."

It isn't easy to come into a game without having practiced with the first team all week. Sanchez hasn't developed timing and chemistry with the starting wide receivers, tight ends or running backs.

That was obvious on a couple of throws. Sanchez threw for Murray, who was streaking downfield with his back to the play. The interception was a miscommunication with receiver Miles Austin.

"I'm not going to make excuses for that," Sanchez said. "I am in charge of the job just like anybody else, whether you get the reps in practice or not. It's my job to go in and there should be a seamless transition. And I thought at times there was."

Part of Kelly's decision to acquire Bradford was living with the chance that he would get hurt. Bradford missed six games in 2011 with the St. Louis Rams. He missed nine games after tearing his ACL in 2013, then missed all of the 2014 season after tearing the ACL again.

That led to Bradford having a reputation for being injury prone. But he was simply driven into the ground by the Dolphins' McCain. Last year, a similar defensive play broke Foles' collarbone. There isn't much anyone can do in a situation like that.

After trading for Bradford, Kelly signed Sanchez to a new contract. He hasn't had a quarterback start more than nine games in a row in his three seasons as head coach of the Eagles.

If Bradford can start next week against Tampa Bay, he would be the first. That would be his 10th start in a row.

If Sanchez starts, Kelly will again be managing a change at quarterback. The coach will be counting on Sanchez improving with more practice and game time.

"I'm sure we can get a little more familiar, of course," Sanchez said. "Is that only going to get better with repetition and practice? Of course. The point was, just get in and win the game and unfortunately that didn't happen. But we have a long season ahead of us and we just have to be ready to play."

Sanchez may be ready, but it's unknown how long he'll be needed. That may turn out to be the deciding factor in an Eagles season that is hanging in the balance.