Ambry Thomas is playing his way off 49ers roster after preseason Week 1

Ambry Thomas had a long way to go to make the 49ers' 53-man roster, and his efforts in the preseason opener didn't help matters at all.

Preseason football is about two things: getting players and coaches into regular-season rhythm and evaluating players who are on the fringes of making the 53-man roster.

Cornerback Ambry Thomas, the fourth-year pro who has been nothing but consistent since being selected in Round 3 of the 2021 NFL Draft, probably isn't earning any points toward hanging around into the regular season.

The Niners took on the Tennessee Titans for Week 1 of the preseason, a game in which head coach Kyle Shanahan sat most of his starters on offense and defense, letting plenty of backups and niche players get extensive field time.

With the limited opportunity, Thomas at least got to start but committed at least two gaffes that'll hinder his slim roster chances.

Ambry Thomas hurts roster chances by committing 3 key mistakes

Tennessee took advantage of some poor San Francisco coverage on its opening kickoff return, as wide receiver and return specialist Kearis Jackson returned it 63 yards that helped set up the Titans' first touchdown of the evening:

Thomas, No. 20 on the right side of the 49ers' formation, misses a tackle on the play, allowing Jackson to break free.

Then, later that drive when the Niners were holding the Tennessee to a third-down try in the red zone, Thomas committed a defensive hold that gave the Titans a fresh set of downs and the ball on the 1-yard line.

Late in the second quarter, Thomas whiffed on a tackle on a screen play, failing to take down running back Julius Chestnut that allowed a 36-yard gain on 3rd-and-10:

Adding injury to insult, Thomas exited at halftime with a forearm injury and didn't return.

Ouch.

San Francisco already has its starting crop of cornerbacks set: Charvarius Ward, Deommodore Lenoir and Issac Yiadom, while Rock Ya-Sin and Renardo Green are all but guaranteed roster spots, too, likely leaving just one more spot on the regular-season depth chart.

Thomas is one of a number of others hoping for a role. Judging by his preseason Week 1 efforts, he won't be getting it.

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