RENTON, Wash. -- Mike Davis is expected to return to the Seattle Seahawks' backfield this week and Chris Carson could do the same at some point this season.

That's good and potentially even better news for an offense whose 20th-ranked running game can use all the help it can get. For one-time starter Thomas Rawls, though, it doesn't bode well for his chances of climbing back up from what looks like a pretty long fall down Seattle's depth chart.

Rawls was a healthy scratch in Week 11 for the second time this season, then played only one snap in the team's win over the 49ers on Sunday.

"He's still in there battling," coach Pete Carroll said Monday when asked where Rawls fits into Seattle's backfield rotation. "Thomas is healthy, and this week we just had to make a choice and we'd been anxious to see how Eddie [Lacy] does, so we'll see how this week turns out."

J.D. McKissic started Sunday's game but Lacy got the majority of the work, carrying a season-high 17 times for 46 yards and adding three catches for 15 yards. He played 35 snaps, also a season-high, compared to 29 for McKissic. The fact that Rawls got only one snap -- he didn't get the ball on that play -- stood out even more with the way Seattle was in control of the game throughout the fourth quarter, leading by at least 15 points until the 49ers found the end zone as time expired.

Pressed for reasons why Rawls hardly played Sunday, Carroll said the coaching staff was intent on seeing what Lacy could do and that the more other running backs were mixed in, the less on Lacy there would be to evaluate. The Seahawks decided earlier this month to give him a shot to take over, figuring that sharing carries with Rawls wasn't doing their struggling running game any favors, but Lacy promptly injured his groin and missed the following week. Seattle eased him back in Week 11 against Atlanta.

"We knew this [past] week now he would be ready to go and handle the load, so we took a chance to see how he did," Carroll said.

Lacy averaged an entirely unimpressive 2.7 yards per carry Sunday, and Carroll noted that he missed opportunities for bigger gains on a couple runs, but he looked beyond the numbers and liked what he saw.

"I really liked that he ran hard and ran tough, and you could see him knocking piles forward," Carroll said. "Like I said, the protection wasn't great, but he showed us his style, and we got to feel him. He played throughout the game, and it was the first time we got a chance to do that, so we got a good feel for him."

Carroll then said it's a new week and that the Seahawks are figuring out their backfield plans as they go, noting that Davis will be back this week. He was two quarters into an impressive Seahawks debut in Week 11, having just been promoted from the practice squad a few days earlier, when he strained his groin while being tackled on a screen pass.

Davis had started the game and gained 57 yards on eight touches. The way he was playing might have merited another start the following week and still could this week vs. Philadelphia.

Meanwhile, McKissic has been an effective dual-threat weapon out of the backfield, giving the Seahawks some of what they had hoped to get from oft-injured third-down back C.J. Prosise. McKissic gained 46 yards on eight combined carries and receptions Sunday, and it doesn't sound like Carroll has any plans to reduce his workload in order to get Rawls or anyone else more involved.

"Isn't he exciting? Golly, we've just got to get it to him more," Carroll said Monday on 710 ESPN Seattle. "Everything he does is fun to see. There's nobody that plays harder, there's nobody that competes more at every step he takes. So we just need to just keep getting it to him in different ways and good things happen. He looked great yesterday."

And as if Rawls wasn't already having a hard enough time seeing the field, Carson's potential return would make that even harder. The rookie seventh-round pick began the season as the Seahawks' starter and was clearly their most effective running back until he went down in Week 4 with ankle and knee injuries. He remains Seattle's leading running back -- but still behind quarterback Russell Wilson -- with 208 yards rushing.

Carson had surgery on his ankle and is eligible to come off injured reserve now that he's missed the requisite eight weeks, but he won't be ready to play for a matter of weeks, if at all. Carroll's comments left the impression that it's more of a possibility than something the team is absolutely counting on.

"This week will be really important and we'll have a lot of information going forward, and there's a chance, so we'll hold out hope for him," Carroll said. "I know he's dying to play and he's done everything he could possibly do and he just handled the rehab up to this point well beyond expectations. We'll see what that means."

Carroll was similarly noncommittal about Seattle's plans at running back in the near term.

"We're just gathering information and fortunately we got a win and we'll keep going," he said. "There's a lot of football left and we're hoping that we can continue to find the very best of it and be really effective, so we'll see what happens."