Christian Ponder has not been cleared to practice after sustaining a concussion last Sunday against the Chicago Bears, and Frazier said the Vikings were not planning on having Ponder for the team's upcoming game against the Baltimore Ravens.
That means Cassel will be in line to start his third game this season. He took over for Ponder last Sunday and led the Vikings to a comeback victory. Cassel completed 20 of his 33 passes for 243 yards with a touchdown and an interception, and he's still the only Vikings quarterback to throw for at least 240 yards in a game.
"Part of it is, what he did in the second half of that ballgame on Sunday, and also, seeing his comfort level with where we are and having a comfort level with him, as well," Frazier said. "But his work on Sunday has a lot to do with it. He did an outstanding job in the second half of that ballgame against Chicago."
Josh Freeman will likely be Cassel's backup Sunday, assuming Ponder is unable to play. Ponder has passed part of the league's concussion protocol, Frazier said, but he can't practice until Thursday at the earliest. If Ponder can get on the practice field Thursday, Frazier said he could consider starting Ponder.
But Cassel seems all but locked into the job for Sunday.
After signing a two-year, $7.4 million deal in the offseason, Cassel led the Vikings to their first win on Sept. 29, when Ponder (cracked rib) was unable to play. Cassel threw for 248 yards in the victory over the Pittsburgh Steelers in London, and he also started the Vikings' first game after their bye. But the Carolina Panthers intercepted Cassel twice on Oct. 13, and once the Vikings gave Freeman a start in their next game, Cassel seemed relegated to a backup role.
Frazier put Ponder in the starting spot once Freeman went down with a concussion and said afterward that he would consider only Ponder and Freeman as potential starters. But Cassel helped the Vikings get a win once Ponder got hurt Nov. 7 against the Washington Redskins, and he played well in relief Sunday. That's been enough for him to get another chance to start.
"You get as frustrated as you let yourself get frustrated," he said. "Each and every day, I've tried to work hard, I've tried to stay in the right mind frame because I think anything other than that takes away from doing your job and being able to go out there and perform when your number is called.
"I'm excited about the opportunity to play with the guys again on Sunday and hopefully we'll go out and have a great game."