The San Francisco 49ers lost defensive tackle Alfred Collins for the season with a torn patellar tendon. The team will have to decide if they want to make an outside move or if they want to lean on the players on the current roster. 

There are a few players who will immediately be called upon to step up.

3 San Francisco 49ers Who Must Step Up With Alfred Collins Absence 

C.J. West 

The second-year defensive tackle is now one of the more experienced options on the line. West went from someone pushed far down the depth chart to having a legitimate chance at a starting spot. West joined Collins as the top two run defenders on the roster, and the only legitimate options to be nose tackle. 

The team has Osa Odighizuwa as the three-technique, and his role will not change. However, West is the one who will play the one and zero techniques. Until they can trust depth to fill that role, West will go from a small rotational spot to a potential starter.

If the 49ers sign a defensive lineman, it will likely be a big, run defending type of player. 

Gracen Halton 

The rookie fourth-round pick was going to get eased into the mix. Now, he is likely the third man in the rotation. West will still hardly play on passing downs. The plan is for Mykel Williams to eventually slide inside on these snaps, but he is out. So, Halton is going to play a big role on the obvious pass downs and two-minute drill. 

If Halton excels here, the team will continue to put more on his plate. This is a great way for the unknown rookie to make a name for himself. 

James Thompson  

The rookie UDFA went from someone barely fitting onto the roster to someone likely to see the field. Thompson is not a pure nose tackle, but he can handle run duties well enough that he would backup West, while Halton will backup and complement Odighizuwa. 

West has only played 20 or more snaps in seven games in his career. He has never played more than 44% of the 49ers defensive snaps. His role will increase, but they have to lean on the depth.

Thompson has impressed every step of the way and could end up being a great find for the team. Still, they did not expect him getting into the mix this early on.