Against the Dolphins on Sunday, Colin Kaepernick completed 29 of 46 passes for 296 yards and three touchdowns, while throwing one interception.
He also racked up 113 yards on the ground.
Although Kaepernick has found success in Chip Kelly's system, Greg Cosell is not convinced he is the long-term answer for the 49ers.
"I don't think you can go into next season with Colin Kaepernick as your clear starter and say, 'He's our guy, we're ready to go,'" Cosell said on KNBR 680 on Wednesday morning. "Now again, there are five more games to play. I've been very realistic and objective in evaluating him just because you had to see him, you had to give him a chance to work through this offense.
"I think Chip has done a really good job overall with defining throws for him -- the intitial read -- so the ball can come out. He still, obviously, has a long way to go when that initial read is not there. That's not a strength of his game. He's not a progression reader. It's a quick-timing offense.
"And then they have to decide how they feel about the rushing yardage ... that offense almost demands that the quarterback be a significant running threat. How much can a quarterback run in the National Football League, both by design and improvisation? That's a question that most people I think come down on the side of, 'He can't do it too much.'"
What does Cosell think when he sees Kaepernick perform the way he did in Miami?
"More than likely, history in the NFL, suggests that you can't survive that way and live in that world on a weekly basis," Cosell said. "He has certain things he can do and I think that Chip has accentuated that with the style of offense ...
"The longer he's in the pocket, the less effective he is, the less he sees. He has very poor footwork and balance. Can you camoflauge those things and compensate for those things? You can, up until a certain point. He's still a work in progress and he has a certain skill set that at times shows spectacularly and gets people excited."
Kaepernick, who requested permission to seek a trade in the offseason, can opt out of his contract after this season. If Kaepernick does not opt out, the 49ers would have to decide whether to retain him at his scheduled pay of $14.9 million for the 2017 season.
"He's not a precise, ball-placement thrower in the short and intermediate passing game, which is the foundation of the Chip Kelly offense, so that's a concern as you go forward," Cosell added. "Kaepernick in many ways is a highlight quarterback because the runs get you excited.
"How important are the runs in the context of being a consistent week-to-week quarterback who can make throws when needed?"