Michael Crabtree was back at practice Thursday after working out on a side field with trainers last week. Jim Harbaugh said the receiver's performance this week will determine how soon Crabtree returns to the active roster and, eventually, to the playing field.
Crabtree, who is still on the physically-unable-to-perform list following May Achilles' tendon surgery, was allowed to join practice with teammates two weeks ago. He did so in the run-up to the Panthers game Nov. 10. But he worked out by himself last week.
He again was working by himself at the start of Thursday's session. That, however, turned out to be an extended warm-up period for the receiver, and he later joined teammates at practice. The 49ers have until Tuesday to remove him from PUP and place him on the 53-man squad.
Harbaugh said that move could occur sooner than that, leaving a possibility, at least, that Crabtree could play Monday against the Redskins.
Crabtree's return to the lineup promises to bolster a 49ers passing attack that currently ranks last in the NFL. Only two 49ers pass catchers - Vernon Davis and Anquan Boldin - have touchdown receptions this year. Last year, Crabtree was by far Colin Kaepernick's favorite target, and Crabtree became the first 49ers with more than 1,000 receiving yards since Terrell Owens in 2003.
Et cetera - Defensive starters Justin Smith, Ray McDonald and Tarell Brown were not on hand for the start of practice. Smith usually is given a day off during the week. McDonald (high-ankle sprain) and Brown (ribs) are unlikely to play against the Redskins. If that's the case, they will be replaced by Tony Jerod-Eddie and Tramaine Brock respectively.
Harbaugh said that Brown will not go on injured reserve, which would end his season. Asked if Brown had cracked ribs, Harbaugh said, "He's working through something. I wouldn't call it cracked ribs. I'm not going to define it. He's got an issue he's working through. Gonna take a little bit of time.
* Another wideout, rookie Quinton Patton, also was working out on a side field as practice began. He's coming back from a broken foot suffered in Week 4. Harbaugh said Patton would return to practice "very soon."
* Rookie Marcus Lattimore is going through his first-ever NFL practice today, Lattimore suffered a gruesome knee injury in October, and the fourth-round pick will not play this season. Lattimore has said he's been going through his rehabilitation with this day in mind. He can practice with the team for three weeks at which point the 49ers are expected to place him on injured reserve.
* Guard Mike Iupati (knee) and tight end Garrett Celek (hamstring) also did not practice. Iupati will not play on Sunday and will be replaced at left guard by Adam Snyder.
***UPDATE*** This blog was changed to reflect that Crabtree did, in fact, practice with teammates on Thursday. A previous version said he did not.
-- Matt Barrows