Carson Palmer has been so impressed by the top three Cardinals running backs this season he believes each of them deserves to start and get 25 touches a game.

Then the Cardinals quarterback considered that math for a second.

"When all three are healthy, I don't really see that happening," Palmer said. "But they're all very special."

That's the Cardinals' situation now, as running back Andre Ellington primes for his return from a sprained knee on Sunday against the

Lions, giving coach Bruce Arians his full complement of backs for the first time since the season-opening win over the Saints.

Back then, Ellington was the clear No. 1 option, while many waited to see if Chris Johnson had any game left and if David Johnson could contribute as a rookie. A month later, all three are desirable choices, but Arians isn't hiding how he plans to divvy up the playing time.

"It's not hard, because the young guy (David Johnson) sits down," Arians said.

Chris Johnson has been a revelation as the featured back and will remain a big part of the game plan. Johnson has carried the ball 68 times for 302 yards and two touchdowns this season. He is fifth in the NFL in rushing yards and is averaging 4.4 yards per carry after failing to garner much free agent interest before training camp.

Not only has he rushed the ball well, Palmer raved about Johnson's ability in pass protection despite being a late addition.

"He's a great protector (and) really, really smart," Palmer said. "He picked up the offense as fast as anybody picked it up since I've been here."

Ellington is a guy who the Cardinals have counted on as a focal point of their offense, health permitting, since halfway through his rookie season in 2013. Ellington had 12 carries for 69 yards and a score before going down against the Saints, but the injuries have been an issue dating back to last year.

"This ain't cheerleading, it's football," Ellington said. "It's bound to happen. You're going to get injured."

David Johnson had zero carries in the opener with the other two healthy, and while Arians seems set with Ellington and Chris Johnson as his main options, David Johnson has at least forced him to give it some thought.

He had a pair of crucial errors on Sunday – fumbling away the opening kickoff and dropping a touchdown pass – but has shown star flashes, racking up a 108-yard kickoff return for a score, two receiving touchdowns of more than 20 yards and a 5.7 yards per carry average on 15 rushes.

"We've got a lot of talented guys in that room," Chris Johnson said. "Any one of us can go out there and get the job done. It's a situation where each of us have different things in our game that we're good at. Coach B.A., he knows the right way to get that out of us to maximize our talent."

Ellington said a running back rotation is desirable because it allows all of them to stay fresh, and it also gives Arians free reign to dial up varied play calls.

"I always say, it's like B.A. is playing Madden," Ellington said. "He has so many talented players that he can pretty much call anybody at any time, and we're all able to execute."

Arians likes to spread the ball around, which is why 25 touches for any one player are unlikely at this point. He also likes to throw, and the deep shots have helped make the Cardinals one of the highest-powered offenses in the league. But when they have gone to the ground game, it's also been effective.

The Cardinals gained 113 yards on 21 carries in Sunday's 24-22 loss to the Rams, the fourth straight game registering 110 rushing yards or more to begin the season. They hadn't done that since 1988.

With Ellington in the fold, it's another weapon Detroit must handle out of the backfield.

"It's a handful defensively getting ready for those three," Palmer said.