SANTA CLARA -- A "Keep Kap Safe" campaign is in full swing at 49ers headquarters, only 2½ weeks before Colin Kaepernick officially enters his first full season as their starting quarterback.

The 49ers' latest step in protecting Kaepernick is to suit him up in a black practice jersey, reminding defensive teammates he's off limits.

No, he's not "working through something," as coach Jim Harbaugh vaguely says of his players' injuries. Kaepernick remains a picture of good health, still cover-boy perfect.

"I'm not a fan of the jersey," said Kaepernick, the only one of four quarterbacks modeling that black shirt -- with a red No. 7 on it.

Harbaugh's not a fan of seeing his franchise quarterback encounter close calls with the 49ers' ever-feisty defense.

"There was a play (Monday) where we were going against our (starting defense), and as the defense was running a stunt, Ahmad (Brooks) came free and got a little close to Colin," Harbaugh said. "The jersey is a way to re-emphasize 'stay away from Colin Kaepernick,' so we don't get anything freakish happening in practice."

Asked about Brooks' pass rush, Kaepernick said it "didn't scare me at all."

Kaepernick stands to see a lot more action in Sunday night's exhibition game against the Minnesota Vikings. He played only four snaps in Friday's win at Kansas City and 12 snaps in the Aug. 8 opener against Denver.

"I would play every snap if they let me," Kaepernick said.

Colt McCoy will be the second quarterback in for the 49ers on Sunday, Harbaugh said, declining to state whether Scott Tolzien or rookie B.J. Daniels would be third.

Daniels, however, is now getting as many reps on the second-string offense, and he's no longer splitting time at running back or wideout.

With that backup race so wide open, the 49ers may even bring in Seneca Wallace for a tryout, Comcast SportsNet Bay Area reported. Wallace was released by New Orleans earlier in the week.

Keeping Kaepernick upright as the starter remains the 49ers' utmost priority. He hasn't taken too severe of a hit in his 16 games (10 starts), and he's been sacked 21 times in over 325 passing downs. He's also had 90 career carries, leaving him prone to more hits.

"The more you put the QB in harms way, the more harm will come to him," Arizona Cardinals coach Bruce Arians told reporters at the February scouting combine.

Kaepernick's mobility helps keep him safe, as does one of the league's best offensive lines.

"It's easier because he just makes so many plays with his feet," left tackle Joe Staley said of blocking for him. "He can get you out of a lot of bad situations and make you look good. He's so athletic back there."

After Kaepernick led the 49ers to last season's Super Bowl, he has earned celebrity status by way of endorsements, as well as high praise among NFL observers.

Kaepernick reacted humbly Wednesday at the notion he could become one of the NFL's greatest quarterback ever, as proposed by ESPN analyst Ron Jaworski.

"To me, it's a great honor what he said. I'm very flattered," Kaepernick said. "But at the same time, I haven't played a full season yet."

  • Harbaugh ended his media session with a pointed defense of why he spoke so strongly last year in support of wide receiver A.J. Jenkins, who was traded Monday to the Chiefs after a zero-catch rookie season.

    "I really feel the same as I did a year ago when I made those comments: That I don't think it's fair to bully or label a young player," Harbaugh said. "Though I fully understand that people are entitled to their opinion and their perspective. However, I would appreciate if the criticism is directed toward me. I'm responsible, and I certainly accept that. Actually, I welcome it."

    Asked to clarify what he's "responsible" for, Harbaugh replied: "I'm responsible. I'm responsible for helping pick the draft picks and fully responsible for coaching the players up. So I willingly accept those responsibilities."

  • Kendall Hunter will suit up Sunday and play in his first game since tearing an Achilles on Nov. 25. "I feel like I'm getting back to myself," Hunter said. "Whatever coaches call or want, I'm there and ready for it."

    Hunter is on track to remain Frank Gore's top backup. Hunter's average of 5.2 yards per carry led all the 49ers' running backs last season before he got hurt in New Orleans. He finished with 72 carries for 371 yards and two touchdowns.

    "He has been back in action in practice," Harbaugh said, "and when you dive back into the action, your senses, your instincts come back. And he appears to have that."

  • Jon Baldwin, acquired from the Chiefs for Jenkins, is slated to make his 49ers debut Sunday, Harbaugh said. Kaepernick welcomed his new target and praised his catching ability. But Kaepernick added: "It'll take time to really get a feel for him."

  • Special-teams ace Bubba Ventrone returned to practice after being sidelined since Aug. 8 with an apparent leg injury.

  • Rookie tight end Vance McDonald practiced for a second straight day and should play Sunday, having been sidelined since the Aug. 8 exhibition opener with an undisclosed injury.

  • Linebacker Nate Stupar and safety Darcel McBath were not present at the start of practice.

    For more on the 49ers, see Cam Inman's Hot Read blog at blogs.mercurynews.com/49ers. Follow him on Twitter at twitter.com/CamInman.

    SUNDAY'S EXHIBITION

    Minnesota (0-2) at 49ers (1-1), 5 p.m. NBC