Thomas was released by the 49ers on Tuesday.
Thomas originally joined the 49ers in June after spending the past four seasons with the Commanders. The 33-year-old was then released Aug. 9 before re-signing with the team Thursday, but he did not make it through San Francisco's final cutdown to the 53-man roster. Thomas could be a candidate to come back on the practice squad, otherwise he'll look for an opportunity elsewhere ahead of the regular season. Meanwhile, Jake Tonges should serve as the 49ers' top backup behind George Kittle.