Rookie John Skelton and the newly signed Richard Bartel took reps with the first unit in Wednesday's practice. They were the team's only healthy quarterbacks.
Starter Derek Anderson hasn't been cleared to play because of a concussion from last Sunday's 19-6 loss to St. Louis. His backup, rookie Max Hall, went down with a season-ending shoulder injury in that game.
Whisenhunt said he would decide on a starter "later in the week."
Arizona has lost seven in a row and ranks next-to-last in the NFL in offense. The Cardinals have one touchdown in the last three games, and that came on the final play of a 31-13 loss to Kansas City.
Even if Anderson is cleared to play, he might not start.
"We'd have to see how the week goes," Whisenhunt said. "I couldn't say if he didn't practice he would play. Like I said, we'll see how the week progresses."
Bartel, the backup to Daunte Culpepper with Sacramento of the United Football League, said he was hog-hunting -- with a knife, not a gun -- in Texas last week when the Cardinals called.
He had worked out for Arizona two weeks ago but didn't know if he fit in the team's plans.
"They were pretty straightforward," Bartel said. "It felt like a process. I didn't know if it was something that they wanted to do immediately. They had three healthy quarterbacks, but I did have a good workout. It was just hurry up and wait at that moment."
Bartel played for the Washington Redskins against the Cardinals in the final preseason game, completing 12 of 14 passes for 125 yards and a touchdown.
"Part of what you do in the preseason is you look at other players," Whisenhunt said. "When he played for Washington and against us I was very impressed."
Two days after that game, the Redskins cut Bartel, who wound up in Sacramento, playing for ex-Cardinals coach Dennis Green.
Bartel said he knows he has a chance to start but is fine if he doesn't.
"It's exciting and I'm thankful for the opportunity, I really am," he said, "and whatever decision he makes is going to be best for the team and I'm all right with that. So I'll just keep preparing. If I get the call, I get the call. If not, I'll be there to support John."
The 6-foot-6, strong-armed Skelton, a fifth-round draft pick out of Fordham, was the team's third-string quarterback a week ago. He made his NFL debut in the fourth quarter against the Rams, converting a third-and-16 situation with a 22-yard pass to Steve Breaston, then had a 19-yard completion to Larry Fitzgerald. He wound up 3 of 6 for 45 yards.
"I guess last Sunday was like sticking your foot in the pool to test the waters," Skelton said. "Now it's kind of jumping in, I guess. It was good experience and it's just something to build on."
Whisenhunt has said several times that he didn't think Skelton was ready to play, but with his team's slide accelerating, he may have little choice.
Most of Skelton's work in practice has been for the team that simulates the upcoming opponent, so it's difficult to evaluate him, Whisenhunt said.
He said passing game coordinator Mike Miller and quarterbacks coach Chris Miller have spent time after practices working with Skelton "in case this did happen."
"That doesn't replace reps on the field but it certainly has helped him," Whisenhunt said. "He's a lot more comfortable with it than he was in preseason. That's what happens when you have young quarterbacks. He got in the game last Sunday and he handled himself well. It was nice to see that. ... If he has to play a lot in this game, we'll certainly get a good assessment of where he is."