SANTA CLARA Patrick Willis and the 49ers' defense learned the Cleveland Browns had traded running back Trent Richardson to the Indianapolis Colts midway through San Francisco's Wednesday practice.
As soon as the session was over, they flipped on some Browns game film to see what they had in store for them Sunday.
"He's a good running back," Willis said Thursday. "You don't know why Cleveland would let go of a guy like that, but for whatever reason that is, he's a Colt now and that's what we'll have to get ready for."
Despite that Richardson will have only two full practices with his new teammates before Sunday's game, the 49ers said they expect to see a lot of the third overall pick in last year's draft.
"A lot of times when you get a trade like this during the season, it's when a guy was holding out or something, and he's really not ready to go," defensive coordinator Vic Fangio said. "This guy's ready to go. I expect him to play a bunch on Sunday."
Fangio said the 49ers won't alter their game plan. But they had to account for the fact that, at 225 pounds, Richardson is a bigger and more aggressive runner than the Colts' previous starter, Vick Ballard, and his understudies, Ahmad Bradshaw and Donald Brown. Ballard tore his ACL last Sunday and is out for the season.
Rookie safety Eric Reid played against Richardson twice when he was at LSU and Richardson at Alabama.
"He's (a Southeastern Conference) running back," Reid said. "He definitely looks the part, as you can tell. He runs just like it. You've got to gang tackle him. I don't think we necessarily change the game plan. You just recognize it might take a little bit more oomph to get him on the ground."
Injury updates Reid, who suffered a concussion last Sunday, said he's passed all of his post-concussion tests this week and had a successful visit to the neurologist Wednesday. The last step in that protocol is simulated contact, which will occur at the end of the week.
Reid said he was surprised by the concussion because he didn't have any while at LSU and because the hit that caused it, on Seattle Seahawks wide receiver Sidney Rice, was not helmet-to-helmet. Reid led with his shoulder and seemed to take the brunt of the impact with the shoulder.
He said he felt fine shortly after being helped off the field. "I wanted to go back in but they hid my helmet somewhere," he said.
Fangio, meanwhile, said he expected all of his injured starters, including Reid, defensive end Ray McDonald (ankles) and Justin Smith (shoulder) to be on hand for the Colts game. "I think we'll be fine by game day," he said.
Smith was limited in practice Thursday while McDonald missed his second straight day. Reid practiced in a blue jersey that signals to teammates he is to avoid contact. Running back LaMichael James practiced for the first time since spraining his knee Aug. 29.
Another injured starter, tight end Vernon Davis, was seen in the locker room with a bandage around his left hamstring. Davis did not practice Wednesday or Thursday. Asked about Davis' availability, offensive coordinator Greg Roman said, "I don't know what kind of blood he has going through his body, but it heals really well."