It is the second season-ending injury in as many years for Bishop, who missed all of last season for the Green Bay Packers after tearing his hamstring in the preseason opener.
The Packers released Bishop in June, and he signed a one-year deal with the Vikings shortly after that. He had taken over the team's weakside linebacker job from Marvin Mitchell on Sunday, but his time with the Vikings could now be over.
"As we gave him more opportunities, he had shown that he was ready to get a starting assignment," Frazier said. "I wanted him to solidify it through his play in that ballgame yesterday. Unfortunately, he got injured, but he was playing well up to that injury."
Frazier said the Vikings will determine what to do at outside linebacker but that they would keep converted outside linebacker Erin Henderson at the middle linebacker spot.
Mitchell could regain his starting role, or rookie Gerald Hodges -- the team's fourth-round pick last April -- could push for more playing time.