Colin Kaepernick can't play catch-up in 49ers preseason debut vs. Packers

SANTA CLARA, Calif. -- In fairness to San Francisco 49ers quarterback Colin Kaepernick, rust was to be expected as he made his preseason debut Friday night.

Kaepernick hadn't appeared in live game action since Nov. 8 before playing in Friday's 21-10 loss to the Green Bay Packers at Levi's Stadium. Making matters worse, surgeries to his shoulder, thumb and knee kept Kaepernick from participating fully in the offseason program, and shoulder tightness cost him nearly two weeks of practice and games in this preseason.

So to even try to compare Kaepernick to Blaine Gabbert in the competition for the starting quarterback job at this point is wholly unfair. It's also the reality of where the Niners are in this exhibition season.

San Francisco coach Chip Kelly has said repeatedly he wants to give Kaepernick and Gabbert an equal shot to win the job. Kaepernick's body hasn't cooperated with that plan. And it has left the 28-year-old trying to play catch-up with time running out in the preseason.

So it was that Gabbert and Kaepernick each played a quarter with the starting offense Friday night, and the unit had its only success with Gabbert at the controls. On two series, Gabbert was 2-of-3 for 14 yards and added a pair of carries for 15 yards. He was behind center when the 49ers scored their lone touchdown of the game.

Kaepernick, meanwhile, looked about as you'd expect him to after such a long layoff. He completed his second pass for 12 yards and a first down, but it was the only time the offense moved the chains with him at quarterback. He finished 2-of-6 for 14 yards to go with four carries for 18 yards.

Stranger things have happened, but with only the fourth preseason game and two weeks of practice before the Sept. 12 season opener, it's hard to see Kaepernick being able to do enough to surpass Gabbert and win the job.

QB depth chart: Gabbert started and played the first quarter, followed by Kaepernick, who played the second. Rookie Jeff Driskel took over in the third and Christian Ponder entered in the fourth to finish the game.

New-look line: After toying with offensive-line combinations for the past couple weeks, the Niners decided to make a change to the starting group. Anthony Davis, who said he hasn't played guard since his freshman year at Rutgers, got the start at right guard in place of Andrew Tiller. That left the Niners with a starting five of (from left to right) Joe Staley, Zane Beadles, Daniel Kilgore, Davis and Trent Brown. With the possible exception of rookie Joshua Garnett wresting the left guard job from Beadles, it's entirely possible that will be the front five when San Francisco opens the season against the Los Angeles Rams.

Who got hurt? Early in the second quarter, receiver/returner Bruce Ellington awkwardly fielded a punt and was left hobbling off the field. He did not return because of what the Niners called a hamstring injury. Defensive lineman Quinton Dial also did not come back into the game after a knee injury. Running back Carlos Hyde suffered a concussion in the first half.

A surprise player who impressed: Tank Carradine hasn't been playing outside linebacker for long, but his transformation from hand-in-the-dirt defensive lineman to stand-up edge player continues to look like an experiment with potential. Carradine shed about 30 pounds in the offseason to make the move, and with Aaron Lynch suspended the first four weeks, there will be no shortage of opportunities for Carradine to work into the rotation. He was all over the place against Green Bay, finishing with two tackles, a sack and a handful of pressures.

When it was starters vs. starters, the 49ers looked ...: For the third consecutive game, it was a pretty solid effort from the starting group. Gabbert led the offense to a touchdown on the second drive, which was an improvement over the first two preseason contests, when such success didn't happen until the third possession. The defense, which was without a number of key players, held up well considering it was on the field for more than 21 minutes in the first half. Most important, the Niners didn't have any turnovers from the starting group, though Kelly probably would say he'd have liked the defense to come up with one.

One reason to be concerned: The 49ers don't lack for intriguing talent on defense and could exceed expectations if much of that talent develops. But it's going to be difficult if that group is on the field all the time. The Packers had the ball for 21 minutes, 11 seconds in the first half, largely because the Niners only had five first downs and went three-and-out three times. Kelly's up-tempo offense can wear defenses down if it's working, but if it's not, it's his own defense that feels the burn.

Sitting it out: While many teams use the third preseason game to have their starters play extended time, the Niners gave three key veteran defenders the night off. Linebackers NaVorro Bowman and Ahmad Brooks and safety Antoine Bethea watched from the sidelines in street clothes. End Arik Armstead (shoulder), receiver Bryce Treggs (knee), linebacker Nick Bellore (knee), defensive lineman Glenn Dorsey (knee) and receiver DeAndre Smelter (hamstring) also did not participate.

Up next: The 49ers will wrap up the preseason on Thursday night in San Diego.