PHOENIX — If Ken Whisenhunt is a man of his word — and I believe he is — Kurt Warner will be the Arizona Cardinals' starting quarterback when they open the regular season in 13 days.

What choice does Whisenhunt have?

He said before training camp that Warner would have an opportunity to win the job from Matt Leinart.

He told Warner the same thing.

Given those promises, there's no way Whisenhunt can stick with Leinart after his horrid three-interception performance against the Oakland Raiders on Saturday.

ESPN's Chris Mortensen reported yesterday that Warner is "expected" to be named the starter, and that the Cardinals have concerns about Leinart's arm strength and consistency.

I don't know who Mortensen's source is, but I do know he's not the type to make things up.

Warner likely will be named the starter. What we don't know is when Whisenhunt will make the announcement or how Leinart will respond.

I've argued vociferously that Leinart should be the starter because the organization needs to find out whether he can be an elite NFL quarterback.

But I can understand Whisenhunt's decision to go with Warner.

First, he has been the better quarterback throughout training camp.

Second, if Whisenhunt sticks with Leinart, there could be serious repercussions in the locker room.

Some players will wonder if they can trust anything their head coach says, given his oft-repeated quote, "I think we've shown we will play the best players."

Others will perceive him, fairly or unfairly, as a management stooge.

Either way, that's a deep pile of trouble Whisenhunt would be stepping into.

The bigger story, however, is not who will be the starter on Sept. 7 in San Francisco. It's whether Leinart has what it takes to play in the NFL.

His uneven performance last year before he broke his collarbone was somewhat understandable. He had little experience and he was playing in a new system. It would have been a surprise if he didn't struggle.

But there's no excuse for the way Leinart played Saturday. He knows the offense. He's healthy. The Cardinals aren't asking him to be Tom Brady.

And he has a 2.8 passer rating?

Yikes.

Was Leinart a product of all the talent around him at USC? Good question.

An average quarterback is going to look good when he has a massive offensive line to protect him, a slew of talented receivers to throw to and Reggie Bush and LenDale White in the backfield.

Leinart could have assuaged those suspicions had he played well this year. All he's done now is confirm them.

The Leinart bashers — and there are plenty of them — will no doubt bring up his nocturnal habits. But the Cardinals have raved about Leinart's work ethic and discipline. Unless they've been lying, this isn't about unflattering photos on the Internet.

Leinart may — gulp — just not be good enough.

Think about that. Think about what it means if it's true.

The Cardinals will have wasted another high first-round pick. And their quarterback of the future will be the 37-year-old Warner, who will be a free agent after the season.

(This might not be a bad time for Warner's agent to re-open contract negotiations.)

It's not the most comforting of situations, and all because Leinart couldn't hold onto a job he didn't earn in the first place.

I still think Leinart has what it takes to succeed on Sundays.

But I have to admit, my belief is waning.