TEMPE, Ariz. -- Coach Bruce Arians says running back Andre Ellington "should be ready to go" Sunday at Detroit.

If so, the Arizona Cardinals will be close to the offense they envisioned before the season started.

The only possible exception is tight end Darren Fells, who didn't practice on Wednesday with a hip injury. Jermaine Gresham has been getting significant playing time at that spot, too.

Ellington hasn't played since the opener due to a sore knee. He was listed as limited in practice but said afterward, "I feel pretty good. I'll be ready to go."

In Ellington's absence, veteran Chris Johnson got most of the playing time at running back. Johnson is fifth in the NFL in rushing with 302 yards, averaging 4.4 yards per attempt.

Quarterback Carson Palmer was effusive in his praise of Johnson.

"Chris is so good at putting his foot in the ground and getting north and staying skinny through holes," Palmer said. "He plays with so much speed in his cuts. I think that's one of his greatest assets. He's a great protector, really, really smart. He picked up the offense as fast as anybody picked it up since I've been here."

Ellington, Palmer said, "is a dual threat. He's as good a receiver as he is a back. ... He's so quick and elusive and has breakaway speed."

The third player in Arizona's trio of backs is rookie David Johnson, who has 15 carries for 85 yards. He had a rough game in Sunday's 24-22 home loss to St. Louis, fumbling the opening kickoff and dropping a touchdown pass.

Palmer overthrew the open rookie on fourth-and-two at the Rams 43 late in the game. A completion would have set up an attempt for a game-winning field goal.

Palmer said David Johnson `is like Chris and `Dre, but I think he's got like 35 more pounds on them, so he's a little bit more of a bruising back that can run north and south and run with his pads low."

Asked if it's hard to play three running backs, Arians said, `No it's not hard, because the young guy (David Johnson) sits down."

Whether that really will be the case remains to be seen.

The Cardinals had been the most effective team in the NFL in the red zone before going 1-for-5 against St. Louis. They were 2-of-11 on third downs.

The offensive line, with two new members, had some communication problems last week. Left guard Mike Iupati was back from surgery to repair a torn meniscus and right tackle Bobby Massie was suspended the first four games for violating the NFL substance-abuse policy. After being sacked once in the first three games, Palmer was sacked four times by the Rams and was hit after throwing on several more occasions.

"I think we got it figured out," Palmer said. "We felt really good about it today. We worked on it twice today, just a couple of very simple, correctable mistakes, but I think that's past us. Obviously now you throw in the crowd noise and that issue and we'll be ready for it. We're prepared."

Arians said the team has veteran leadership that will make sure there's no hangover from last week's loss. The fans, though, are another matter.

"We've got work to do. We can't dwell," he said. "They (the fans) have to go work and cry -- and rightfully so until they get another win -- and drink a lot of beer."

The Lions' controversial 13-10 loss at Seattle should make it hard for the Cardinals (3-1) to look past the winless Lions.

"This is a team that was a foot and a half from beating Seattle at home," Palmer said. "If anybody knows how hard that is, we do."