Mike Ditka, who knows the perils of coaching after a layoff, said he likes Jon Gruden's chances of succeeding as new head coach of the Oakland Raiders. But Ditka suggested it won't be easy for Gruden, who will be officially introduced as the Raiders coach Tuesday after a nine-year absence from the sidelines.

“It's a helluva challenge,'' Ditka told USA TODAY Sports on Monday. “Let's face it. It's a big challenge, and I think he's up to it.''

A return to the sidelines for Ditka failed spectacularly. He was 106-62 as head coach of the Chicago Bears from 1982 to 1992 and, after a four-year hiatus, 15-33 as head coach with the New Orleans Saints from 1997 to 1999.

Recalling the experiment, Ditka said a lack of desire undermined him.

“I think there's a lot of ego involved, although you hate to admit it,'' he said. “I want to prove I can still do it and this and that. But if the heart's not in it, I mean totally in it. ... It's really hard to say, 'Oh, I'm going to amp it up and then everything will be fine.' It doesn't work that way.''

A lack of desire wasn't the only issue, Ditka said.

“Personnel is where we really screwed up,'' he said. “I thought that I could really get by with the quarterbacks we had. ... I had every guy named Billy Bob in the world. So put it this way, it was an experience.

“They're glad it's over and I'm pretty glad it's over, too.''

The Raiders have Derek Carr, not a Billy Bob, at quarterback, and Ditka said he expects Gruden to invigorate the Raiders' offense and elevate the entire team.

“It's a great job,'' Ditka said. “It's a great opportunity for him.''