COLLEGE STATION, Texas (AP) — Texas A&M is searching for a way to move on after this weekend's upset loss to Auburn.

The 45-41 defeat dropped the Aggies from seventh to 14th in the poll.

Now Texas A&M has to see if Johnny Manziel's right shoulder is OK and figure out how to improve its porous defense before hosting Vanderbilt on Saturday.

Manziel missed a series in the fourth quarter against the Tigers with the shoulder injury before returning in the loss.

Coach Kevin Sumlin didn't provide an update on the severity of his injury after the game Saturday night, but didn't think it was a factor in the defeat.

"He came back in and played," Sumlin said. "I don't know how to measure pain. He didn't say anything to me; he just said that he was ready to go. We were able to move the ball; I don't think that was the case. We had a breakdown in protection a couple of times in the second half, which that's not his fault."

He was injured when he bulled into three defenders and was drilled hard into the ground on his right side late in the third quarter. He looked uncomfortable when he returned and was constantly moving and rolling his right arm. Though Sumlin wouldn't speculate on how he was feeling, receiver Malcome Kennedy said they knew he was in pain.

Manziel threw for 454 yards and four touchdowns, but also had two interceptions Saturday. He ran for a touchdown after the injury, but was sacked for a 22-yard loss on fourth down on the last drive to give Auburn the victory.

Though Manziel couldn't get A&M in the end zone on the last possession, a much bigger problem Saturday — as it has been all year — was the play of the inexperienced defense.

Auburn controlled the game late with its running game and finished with 379 yards rushing.

The performance of A&M's defense Saturday dropped the Aggies to 118th out of 123 FBS teams in yards allowed a game with 494.4. Their run defense is their biggest shortcoming as they've allowed 226.6 yards a game on the ground.

Injuries have forced the Aggies to rely on young players this season. Five of their defensive starters on Saturday were freshmen or sophomores.

Defensive coordinator Mark Snyder said he needs to figure out how to get some of his veterans on the unit to step up and help the younger players.

"There's something to that, but that's what we are here for as coaches. That's our job," he said. "If you don't have that leadership on the field, you have to create that. We have to lead the way as coaches."

The Aggies, who are giving up 33.9 points a game, had trouble getting off the field on third down on Saturday. The Tigers converted three third-downs on their last drive alone.

"We felt like we got them to third-and-long, but third-and-medium would be our downfall," Snyder said. "That is very frustrating."

The Aggies have three straight home games before a trip to No. 13 LSU on Nov. 23. Sumlin said he'll look for his team to correct its mistakes and improve before hosting Vanderbilt Saturday.

"We got a lot of football left, there's no telling what can happen," Sumlin said. "In this league there's a lot of close games, there are a lot of people who lost (Saturday), too. We got to keep playing and we can't dwell on this, we got to move on, but we also got to look honestly at where we are and how we're going to approach things from here on out."