Kurt Warner might be wondering whether he wasted his time trying to teach the quarterback how to become a better pocket passer.

The 49ers quarterback has not had much chance to showcase his newfound skills behind what has been a suspect offensive line this preseason, but ESPN has given Kaepernick a "Thumbs Down" grade so far during the 2015 exhibition season.

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Kaepernick is 5-of-13 combined during the preseason games for 40 yards with zero TDs, zero INTs, three sacks and a safety.

"Despite all of his work this offseason to improve his mechanics, touch and accuracy as a pocket passer under Kurt Warner, Kaepernick is probably going to have to run -- a lot -- this season given the fluid situation on the O-line," ESPN reported.

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"Per Pro Football Focus, Kaepernick was pressured on five of his nine dropbacks against the Broncos, going 0-for-2 with two sacks and a scramble on the five plays."

After San Francisco's 19-12 loss to the Broncos in Week 3 of the preseason, Kaepernick waved off the issues the line has had.

"No, there's not any concern on this team," Kaepernick said, according to the San Francisco Chronicle. "That's what the preseason's for -- to work those things out and see who we have at different positions. That's what we're doing, and we're working to make sure we're ready for the regular season."

His coach, Jim Tomsula, seemed only slightly more concerned.

"O-line-wise," Tomsula said, "we had a little bit of a struggle there."

But it's in the process of repair, he added.

"That will all get cleared up for you this week," Tomsula said. "That whole thing, we'll clear it up and we'll have it for you."

But last spring, Warner, who spent part of the offseason with quarterback coach Dennis Gile working with Kaepernick on his mechanics and other skills, wondered aloud whether the 49ers QB would revert to his previous form under duress.

"For (Kaepernick), it's finding that balance between 'When do I be a quarterback?' and 'When do I be an athlete?' And trying to find that mix between the two," Warner said, according to NFL.com. "... So the real question is going to be, when the bullets are flying and guys are chasing after him does he revert back to being an athlete or have we made some progress in making him more of a quarterback and staying in a quarterback-friendly position to be able to make more consistent, accurate throws down the field?"

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