SANTA CLARA, Calif. -- San Francisco 49ers defensive end Tank Carradine's 2017 might be over after he suffered a high ankle sprain in this past Thursday night's loss to the Los Angeles Rams.

Niners coach Kyle Shanahan indicated after the game that Carradine might not return this season and a decision on his status would be forthcoming early this week.

Rookie Solomon Thomas, who is expected to get more playing time with Tank Carradine injured, is still seeking his first career sack. Ezra Shaw/Getty Images

For Carradine, a trip to injured reserve would undoubtedly come as a major disappointment just as he seemed to be settling into a position where he's comfortable after bouncing around the past few years.

“Tank has got a high ankle sprain," Shanahan said. "We're going to have to get [his MRI] and really decide whether [to put him on] IR or not, because any time you've got a high ankle sprain, it's going to be a while. So we're not exactly sure how long it's going to be. We'll have to decide that probably Monday.”

Depending on the significance of the sprain, Carradine could be back in a month or it could take a bit longer. The Niners do have one of their designated to return spots available and could opt to use that as well, though they already have one of those spots earmarked for defensive lineman Ronald Blair.

Regardless, losing Carradine is a big blow for the defense as he's looked the part of a solid run-stuffer in new coordinator Robert Saleh's 4-3 defensive scheme. And without Carradine, the 49ers will need much more from rookie defensive lineman Solomon Thomas.

Through the first three weeks, Thomas has served as Carradine's backup, though the No. 3 overall pick in the 2017 draft has actually played more snaps and even started a game. Carradine played 78 defensive snaps with seven tackles and a sack before the injury. Thomas, meanwhile, has seven tackles while playing 122 defensive snaps.

In addition to his work as the "big" defensive end along with Carradine, Thomas also gets work in sub-packages as an interior pass-rusher. Thomas is still seeking his first breakthrough performance, though he's offered glimpses of his athleticism with some tackles for loss, particularly running down ball-carriers from the back side.

But with Carradine expected to miss time one way or another, the Niners will need Thomas to begin growing up in a hurry.

"I don't think he's out of position," Shanahan said. "I think we need to move him around a lot. I think in this game [Thursday], I do think he was on the outside more. I'd like to see him on the inside. But, I don't only want to see him on the inside. I think he’s capable of being at all four spots. That's what we like about him. He has the quickness and he has the size to do both, so I think the more we can move him around, the better.

"But, that's also a lot to put on a guy, too. Each position is slightly different. There's different stunts, different coverages, different ways to play protections and stuff. That takes time. We need him to get better. He will get better. You know, he's in his third game in the NFL after missing OTAs, too. I think he has done some real good things. You don't always get those sack numbers. Those come. I think it took (Falcons pass-rusher Vic) Beasley a while to get some sack numbers for us, too, in Atlanta. He ended up getting quite a bit last year. I wouldn't base it all off numbers. I'm very excited with Solomon. I'm very excited that he's on our team, and I think he's going to be a hell of a player for us.”

For their sake, the sooner Thomas can do that, the better.