SANTA CLARA, Calif. -- On a day when the San Francisco 49ers joined the rest of the NFL in trimming their roster to 53 players, coach Chip Kelly also announced that Blaine Gabbert will be his starting quarterback.

In addition, Kelly made it clear that Colin Kaepernick will be No. 2 behind Gabbert and veteran Christian Ponder will be the team's third quarterback when the Niners open the season Sept. 12 against the Los Angeles Rams on Monday Night Football.

"Right now, I have met with our quarterbacks. Blaine is No. 1 and he'll start versus the Rams, and Kap is No. 2," Kelly said. "We'll only have two guys up [at quarterback] on game day."

It was always going to be an uphill climb for Kaepernick to win the job after he fell behind Gabbert in the spring because he was unable to practice as he recovered from thumb, knee and shoulder injuries. That allowed Gabbert to take the bulk of the snaps with the starters during organized team activities.

At the beginning of training camp, Kelly said there'd still be a competition between Gabbert and Kaepernick for the starting job. They split the first-team repetitions in the opening days of camp before right-shoulder tightness kept Kaepernick out of the first two preseason games and joint practices with the Denver Broncos and Houston Texans.