The 49ers may have not wanted to keep Ambry Thomas into the regular season anyway, but a preseason injury just made things more precarious.

There were plenty of duds from the San Francisco 49ers’ preseason Week 1 road loss to the Tennessee Titans, and one of them was cornerback Ambry Thomas.

Thomas whiffed on a special teams tackle that helped set up Tennessee’s first touchdown. Then, on the ensuing defensive stand, Thomas committed defensive pass interference that gave the Titans a new set of downs after the third-down play, leading to a game-tying score.

Later on in the second quarter, Thomas missed another tackle on a screen play that led to a big gain.

Those mistakes won’t help his already-slim chances of making the 53-man roster.

However, the 2021 third-round NFL Draft choice out of Michigan suffered another bad break, quite literally, as he was seen being carted off the field at halftime.

After the game, head coach Kyle Shanahan told reporters Thomas had suffered a broken forearm and would be out for “some time.”

That paints an uncertain future for Thomas with the Niners.

49ers face tough choice with Ambry Thomas after latest injury

Thomas isn’t expected to participate in the rest of the preseason, and his injury could prevent him from being available when the regular season kicks off in September.

That is, of course, if San Francisco wants to keep him.

Shanahan and general manager John Lynch now face a choice. They can either put Thomas on injured reserve, or they can opt to waive him with an injury settlement, as NBC Sports Bay Area’s Matt Maiocco pointed out.

The former does have some merits. Thomas could be seen as a mid- or late-season reinforcement, someone familiar with the defensive scheme who could be called upon in case of injuries to other cornerbacks.

However, in light of Thomas’ most recent struggles and seemingly yearly mark of inconsistencies, the 49ers may simply wish to make the decision regarding his roster spot sooner than later.