It was a tumultuous season for Texas A&M in 2015. After dropping five of their last eight games this season, the Aggies must now look ahead at what they have coming back and who must be replaced.

The Aggies already have replaced their offensive coordinator and are seeking a new athletic director. The mass exodus at quarterback has been addressed and there are other areas to focus on, including the offensive line where there will be several new faces next season.

Here’s a look at five key players the Aggies must replace before heading into the 2016 season:

RB Tra Carson: Carson put the running game back in Aggies football. He’s the first 1,000-yard rusher in the Kevin Sumlin era at Texas A&M, and was voted the team’s Offensive MVP for the 2015 season. The senior closed out his career with 106 yards against Louisville in the Franklin American Mortgage Music City Bowl in Nashville. It was his seventh 100-yard game of 2015 and the most such games in one season since Johnny Manziel did it in his Heisman Trophy season of 2012. His presence in the backfield will be sorely missed not only as a runner, but also as a receiver.

P Drew Kaser: The senior narrowly missed his pursuit of the FBS record for career punt average. In his final game, Kaser averaged 43.7 yards on seven punts, giving him an average of 46.196 yards on 168 career boots. The FBS record is 46.31 by Todd Sauerbrun of West Virginia (1991-94). Kaser became the second player in NCAA history to average more than 46.0 for his career with a minimum of 150 punts. Kaser owns the school record for punting average in a season, setting that mark in 2013 with a 47.4-yard average. That kind of talent doesn’t come along every day and the Aggies will be hard-pressed to duplicate those numbers in the future.

PK Taylor Bertolet: Another senior who will be hard to replace, Bertolet nailed five field goals this season of 50 yards or more. He hit eight such long-range kicks in his career, which is second-most in school history. A second-team All-SEC player, Bertolet connected on nearly 90 percent of all of his placekicks this season. Counting field goal and PAT attempts, he was 60-for-69. He ranked second in the SEC in made field goals, hitting on 22-of-31 attempts in 2015. He’s only the third Aggie to hit at least 20 field goals in a season and ranks second all-time behind Randy Bullock’s 29 in 2011. Bertolet and RB Jorvorskie Lane are the only Aggies to have multiple 100-point seasons in program history.

QBs Kyle Allen and Kyler Murray: After playing musical chairs in 2015, Texas A&M’s two top quarterbacks decided to leave the program. As a combo, the two will be hard to replace,  because both had their plusses. But help is on the way. Oklahoma transfer Trevor Knight is on the scene and brings an impressive resume with him. Allen threw for 2,210 yards and 17 touchdowns, getting the lion’s share of the snaps in 2015. Murray threw for 686 yards and five touchdowns but also rushed for 335 yards and one score. It remains to be seen if Knight can produce similar numbers. His 2014 numbers were impressive (2,300 passing yards, 14 TDs and 339 rushing yards, five TDs) and he does have that memorable Sugar Bowl victory over Alabama on his record.

RT Germain Ifedi: The junior recently declared for the NFL draft. The 6-foot-5, 325-pounder was among the leaders in a senior-laden line that must be rebuilt in 2016 if Texas A&M is to return to its fast-paced, high-scoring attack.