Adding Crabtree to the mix for the 49ers (7-4) would provide a big boost to a receiving corps that made significant strides in a 27-6 win at Washington on Monday night. Crabtree became Colin Kaepernick's top target last year and had career bests of 85 receptions for 1,105 yards and nine touchdowns.
"I'm good," Crabtree said but he wouldn't elaborate. He was activated from the physically unable to perform list Tuesday to the 53-man active roster.
Harbaugh won't tip his hand too early in the week, while also noting that everything depends on how Crabtree gets through practice.
"Good meetings this morning. Good sessions there. Bright-eyed and ready to go," Harbaugh said before the team practiced Wednesday. "Optimistic like I said the other day. Hope for the best and we'll have a plan if he's not able to go. It's pretty much that simple."
Mario Manningham continues to impress playing opposite Anquan Boldin after three games back following knee surgery last year. Manningham hopes his unit can build off a strong performance and develop some consistency.
"We've just got to do it every week. We can't be inconsistent," Manningham said. "We've got to come out like that every week."
Manningham and tight end Vernon Davis each made four catches at Washington, while Boldin had five receptions and a pair of touchdowns.
Now, if Crabtree is back in the mix, defenses will have a harder time double-teaming Davis downfield.
"It will be great to have Crab back. He's a great talent," left tackle Joe Staley said. "Everybody knows what he can do and is excited to see him back out there. I know he's excited to get back out there, the way he competes and all the hard work he's put in to get back."
Kaepernick isn't ready to guess whether he might be throwing passes Crabtree's way again this weekend.
"That's going to be his call 100 percent," Kaepernick said.
Crabtree has made steady progress back from his injury. He tore his right Achilles tendon during 7-on-7 drills in an organized team activity May 21 then had surgery. The NFC champion Niners said from the beginning they thought he would return this season after Crabtree was a huge reason the franchise reached the Super Bowl again for the first time in 18 years.
Rams coach Jeff Fisher is preparing his defense as if Crabtree will be on the field, and prepare for a variety of ways Crabtree might be utilized. He noted "it's hard for us to predict."
"It gives them an additional weapon. Michael's an outstanding player. Hope he might wait another week," Fisher said. "We're expecting him to play. You go back and look before the injury and what he did for them, and we're familiar with that. Our young group of DBs is going to be challenged. ... Certainly you're not going to play the player if he's not fit to play, 100 percent and fully recovered from the injury."
Everybody involved is eager to see what Crabtree's presence could mean to make the offense that much more explosive. San Francisco's passing attack sits in last place at 32nd in the NFL.