College Football Rankings 2013: Biggest Risers and Fallers After Week 13

The post-Week 13 AP Top 25 college football rankings have been released, and multiple teams were big risers or fallers after a wild week of play.

A few top BCS contenders were knocked off in surprising fashion this past week, while multiple under-the-radar teams continued to make a push up the rankings. Some of the bigger winners were those previously ranked just outside the top five as now they'll have an even better shot at finishing high up in the BCS standings.

The week's biggest losers will have to finish out the season strong if they have hopes of competing in some of the nation's top bowl games. A few teams really hurt themselves in Week 13, though, so it might not be enough to simply win out. They'll need some help from other teams along the way.

The AP Top 25 certainly looks interesting after this week's slate of games.

Riser: Auburn (No. 6 to No. 4)

Auburn may have only jumped two spots in the polls, but they leap-frogged two very good football teams in the process. Sure, both Baylor and Oregon lost in Week 13, but the fact remains that Auburn has now supplanted both of them in the top five.

Auburn's lone loss this season came to LSU when they were ranked No. 6 in the country. Since then, they've beaten three ranked teams and have really only played three close games.

Their offense is dynamic and led by running back Tre Mason and quarterback Nick Marshall. The duo forms a formidable combination on the ground, and that's exactly why the Tigers are ranked No. 2 in the nation running the football.

Auburn takes on No. 1 Alabama in Week 14 in the Iron Bowl, and it will surely be the game of the weekend for college football fans. Auburn is rising at the perfect time as it will take everything they've got to take down the best team in the nation.

Faller: Texas A&M (No. 12 to No. 19)

Johnny Manziel is beginning to struggle at the wrong time. Saturday's loss against LSU marked the first time in his college career that he completed less than 50 percent of his passes, and it's no wonder that the Aggies were unable to beat the Tigers as a result.

A&M has three losses on the season (LSU, Auburn and Alabama), and it doesn't bode well for them considering they haven't defeated a ranked opponent once. They have one more shot when they take on No. 5 Missouri next week; though, Manziel will really have to step up his game.

Prior to the LSU game, it had been the Aggies' defense that would let the team down from time to time. They allow 31.2 points per game, ranking them No. 89 in the nation.

The defense had nothing to do with Manziel's shortcomings against LSU, however.

Riser: Missouri (No. 8 to No. 5)

Missouri is one of the most balanced teams in the nation, and it's no wonder that they're finally in the top five this week.

Their lone loss came in a double-overtime thriller against South Carolina on Oct. 26, but they've cruised to three-straight easy wins since. Actually, the game against South Carolina remains the only close game they've played all season.

The Tigers offense ranks No. 14 in the nation, their defense ranks No. 15 in the nation and their running game ranks No. 18 in the nation. Their passing game must not have gotten the memo, however, as it ranks No. 41 in the nation—note the sarcasm here.

Texas A&M won't be an easy game for them in Week 14; though, they are lucky that Manziel is not currently riding one of his ridiculous hot streaks. With the Alabama-Auburn game also scheduled for Week 14, a victory against A&M will likely result in another rise in the rankings.

Faller: Oregon (No. 5 to No. 12)

Outside of Florida's loss to Georgia Southern, Oregon's loss to Arizona might just be the most surprising of the weekend.

Prior to their loss against Stanford in Week 11, the Ducks appeared to be invincible. Their offensive firepower seemed to be too much for their opponents to handle, and the defense had been doing a great job of holding leads.

The Ducks have now lost two of three, however, and they are in serious danger of not taking part in a prominent bowl game. Their 42-16 loss to Arizona bordered on embarrassing, and Marcus Mariota put together an uncharacteristically poor performance.

His performance was so bad that he'll have to put together a great game against Oregon State next week to just put his name back in the discussion for the 2013 Heisman trophy.

Oregon might be able to crack the top 10 again if they can beat Oregon State, but their two losses this season will continue to haunt them.