This is not quite on the level of recent news, but it is still not a good thing. Outside linebacker Chase Thomas has torn his ACL, according to Eric Branch. Thomas tore it during a workout earlier this offseason, and was in a brace at Stanford during the school's Pro Day on Thursday.
Thomas spent 10 weeks last season on the San Francisco 49ers practice squad. He was on the 53-man roster for five weeks, and off the roster for one week. During his five games on the roster, he played special teams. He is listed as an outside linebacker, but has only played the position for the 49ers in the preseason.
At some point, the 49ers will use the waive/injured transaction and place Thomas on injured reserve. They could give him an injury settlement and part ways, but that would effectively be a full season's pay.
Given that the injury happened after the season ended, it seems unlikely he will be able to play this coming season. They will clear out the roster spot at some point and go from there. The outside linebacker position has some depth, even with the departure of Dan Skuta. Aldon Smith and Ahmad Brooks have extensive experience, Aaron Lynch had a breakthrough season last year as a rookie, and Corey Lemonier did show some things at one point in 2013. I still think the 49ers add another OLB, but it is not a huge priority for now.