RENTON, Wash. -- One of the biggest questions with the Seattle Seahawks heading into the season was whether Thomas Rawls or Eddie Lacy would be the team's primary running back.

Turns out, rookie Chris Carson has been the main man in Seattle's backfield over the first three games while Rawls and Lacy have taken a back seat. That led to a question for offensive line coach Tom Cable -- who coordinates Seattle's running game -- about where those two fit into the plans.

"I think they're going to be damn important going forward," Cable said Wednesday. "Really, we have not got it where we want it and on track where there's a consistency of the right mix and balance and the flow of the game and all those things."

Rawls and Lacy have combined for only 24 offensive snaps through three games, considerably less than Carson's 117 and even the 60 of third-down back C.J. Prosise. But that hasn't been entirely by design.

An ankle injury sidelined Rawls in the opener and then limited him in Week 2 with Seattle wanting to ease him back into action. He only played one snap last week against the Tennessee Titans as the Seahawks were never able to stick with the run, first because they couldn't sustain drives and then because they were trying to make up a two-score deficit for much of the second half. That spoiled Seattle's plans to get Lacy some work after he was a healthy scratch in Week 2. He dressed Sunday but didn't see the field.

Different circumstances led to the same result for the Seahawks in their opener against the Green Bay Packers, when negative plays on early downs continually forced them into passing situations. That's what Cable is referring to when he talks about the flow of the game.

Carson, Prosise, Rawls and Lacy have combined for only 55 carries this season. Carson led the team Sunday with 11 for 34 yards.

"He ran well," coach Pete Carroll said. "Again, the running back needs more carries, and our guys are still young and figuring it out and all that. There weren't enough carries to share, and so Thomas and Eddie didn't get a shot to go much. But it wasn't by their doing. We just didn't get enough plays."

The equation could change this week with Prosise's status uncertain because of an ankle injury he suffered in the fourth quarter against Tennessee. Carroll didn't rule him out for Sunday night's game against the Indianapolis Colts at Century Link Field, but he called it a "significant" injury, which suggests Prosise's availability is in doubt.

Carroll said J.D. McKissic, who's been inactive the first three games, would help fill in on third down if Prosise can't play. McKissic's background as a former wide receiver makes him a better fit than Lacy in the third-down role, which requires pass-catching and route-running skills, but Prosise's absence could still open the door for Lacy to get some work.

Lacy's diminished role through three games -- and Seattle's history of cutting bait early with free agents who aren't panning out -- has led to speculation that the Seahawks could release him. But with his base salary guaranteed, the net cap savings would almost be negligible. And the Seahawks would be parting with depth that they may end up needing given given the extensive injury histories of Rawls and Prosise. Carson has had durability issues of his own dating to high school and college.

No one would have guessed when Lacy signed a $4.25 million contract in March that he'd effectively be fourth or fifth on the team's depth chart and would need an injury to a running back ahead of him in order to get any meaningful playing time. That appears to be the case now, but Cable's comments suggest it won't necessarily be that way for the rest of the season.

"I think they're going to be like gold to us," he said of Lacy and Rawls. "It's just a matter of getting this thing put together."