Colin Kaepernick, who made a rousing debut as the San Francisco 49ers’ starting quarterback Sunday replacing concussed Alex Smith, will take all the first-team reps for the Niners as they prepare to face the New Orleans Saints on Sunday.This comes from none other than Smith, to ESPN.The move seemingly would put Kaepernick on track to start against the Saints; players who receive first-team reps usually draw starts for that week’s game.Harbaugh said earlier Wednesday the QB for the NFC West-leading Niners (7-2-1) could change week to week, and even during the course of a game.Kaepernick went 16 for 23 for 243 yards, two touchdowns and an impressive passer rating of 133.1 in his first NFL start Monday against Chicago. The second-round draft pick out of Nevada in 2011 hardly seemed fazed by football’s big stage. He directed scoring drives and made beautiful throws on the Niners’ initial four possessions and completed 12 of his first 14 passes, with a 57-yard throw to Kyle Williams, setting up Vernon Davis’ 3-yard TD on the next play.Harbaugh rated Kaepernick’s debut start as “A-plus-plus.”Smith said plans to fight for his job once he is fully healthy, but he had yet to be medically cleared Wednesday after missing Monday night’s 32-7 rout of the Bears while recovering from a concussion. He was supportive Wednesday of Kaepernick’s success, even if the second-year pro takes Smith’s starting job as 49ers quarterback.“If you can’t be happy for your teammate’s success you’re playing the wrong sport. Go play tennis or golf or something,” Smith said Wednesday. “That’s ridiculous, I think. That doesn’t belong in team sports, in my opinion. It’s the quarterback position. It gets a lot of attention. We’re going to get talked about.”Harbaugh underwent a follow-up evaluation for his irregular heartbeat Tuesday and said, “believe we’ve got that one licked.” He has quit chewing tobacco and given up the four or five Diet Cokes he was drinking daily after doctors encouraged him to improve his diet and decrease his caffeine intake. Harbaugh underwent a cardiovert procedure last Thursday.“Zero,” he said of soda and dipping. “Cold turkey.”He swears he’s had no headaches as he moves off caffeine.Smith completed 18-of-19 passes for 232 yards and three touchdowns without an interception in a Monday night win Oct. 29 at Arizona for a passer rating of 157.1. Smith then sustained a concussion in the second quarter of a 24-24 tie against St. Louis on Nov. 11. He even threw a touchdown pass with blurred vision six plays after taking the hit doctors believe caused his injury.