49ers-Rams: Jimmy Garoppolo showing his toughness by trying to play, says John Lynch

"Jimmy just looks like Jimmy to me—same confidence, same throws, same balls, same energy, same everything," San Francisco 49ers wide receiver Deebo Samuel told reporters on Thursday. "I don't think he took a step backwards ... It doesn't look like to me that his thumb hurts and he's out there doing a good job this week."

Samuel was speaking of quarterback Jimmy Garoppolo, who is working hard to play in Sunday's regular-season finale against the Los Angeles Rams. He is recovering from a torn ligament and chipped bone in his right thumb, but has thrown during practices on Wednesday and Thursday.

The fact that Garoppolo is fighting his way toward a possible start despite being in significant pain while throwing is a testament to his toughness. Although, general manager John Lynch jokingly said he "knows nothing" about who will start at quarterback on Sunday against the Los Angeles Rams.

"I think Jimmy, again, has shown his toughness by the fact that he's even out there," Lynch said Friday morning on KNBR's Murph & Mac show. "That's a really tough thing for a quarterback to deal with. The thumb is kind of necessary in that throwing process, but he's always been that for us. He's always answered the bell. So the fact that he's been out there practicing has been tremendous effort on his part."

The injury occurred during the 49ers' Week 16 loss to the Tennessee Titans, and forced Garoppolo to miss the Week 17 contest against the Houston Texans. Rookie Trey Lance started that game, earning his first career win.

"Trey played very well last week," Lynch continued. "And Trey, we've been talking about it, and until you see it on the field, you don't know. But we just loved what he's been doing, and I think that it showed after a tough start. He went out there and really played big-time football.

"The good news is that we've got two guys we're extremely comfortable with. I think the fact that Jimmy's been out there and seemingly operating well now, it will come down to just a decision that Kyle [Shanahan] will have to make, probably along with Jimmy, talking with him. 'How comfortable are you? How good do you feel?'

"They've both been getting reps, and they're both ready to play."

Lynch agrees with his star receiver, Samuel. The general manager feels Garoppolo has looked "pretty good" in practice this week. The team just wants to make sure that his thumb can hold up during a game.

Added Lynch: "It's a real injury. You have to see him, and you have to see him over and over, and you have to see that it will hold up. I think it's a very important decision, one we want to make with all the information. So that's kind of what's going on."

The 49ers and Rams kick off their playoff-impacting matchup on Sunday afternoon from SoFi Stadium. If San Francisco wins, the team is in the playoffs. A loss would mean depending on the Atlanta Falcons to knock off the New Orleans Saints on Sunday.

You can listen to the entire conversation with Lynch below.