SANTA CLARA -- Quarterback Colin Kaepernick is listed on the 49ers' injury report as probable for Sunday's game against Arizona with an undisclosed foot issue.
Kaepernick has practiced in full throughout the week, as was the case before the Sept. 22 game against Indianapolis, when he also was listed on the injury report with a foot problem. He had seven carries for 20 yards in that 27-7 loss.
"We don't really talk about what it is he's working through," coach Jim Harbaugh said Friday. "We're complying with the rules, and he's on the report. We haven't altered anything with the practice or game plans."
Kaepernick has had only four carries in the past two games combined. He remains the 49ers' second-leading rusher behind Frank Gore, with 27 carries for 154 yards and no touchdowns (and thus no "Kaepernicking" celebrations).
Whatever the ailment is, Kaepernick is walking and running without any hindrance. He was in socks after Friday's practice in the locker room while shooting baskets into a mini-hoop with teammates Demarcus Dobbs and Nnamdi Asomugha.
"He's taken just as many reps in practice every single practice," Harbaugh said.
So why is he on the injury report?
Responded Harbaugh: "I think you know why. It's been well documented about the injury reports, any type of ailment, injury or however you define it, has got to be on the injury report. We're complying with the rules."
Jacobs, the practice squad's only wideout, is used each week to mimic the opposing team's top receiver.
"I'm every great receiver we go against. I'm that guy," said Jacobs, who's doubled this week as Larry Fitzgerald of the incoming Cardinals. Other receivers he's mimicked: Jordy Nelson (Packers), Reggie Wayne (Colts), Chris Givens (Rams) and Andre Johnson (Texans). He won an in-house, player-of-the-week award for his role as Givens.
"He does a nice job, kind of the 'featured guy' each week," Harbaugh said of Jacobs, who caught a winning touchdown pass two months ago, albeit in an exhibition game at Kansas City.
Jacobs (6-foot, 178 pounds) was a three-sport star at Kennedy High in Richmond before attending Laney College in Oakland and then transferring to Utah State, where he excelled as a receiver and return specialist.
For more on the 49ers, see Cam Inman's Hot Read blog at blogs.mercurynews.com/49ers.