Back-up center may return to action by midseason.

LATROBE — Rookie offensive lineman Marvin Philip is a lot more valuable to the Pittsburgh Steelers than he was when training camp opened less than two weeks ago.

Philip didn't figure in the Steelers' immediate plans when they drafted the former California center in the sixth round in June. Jeff Hartings, their center since 2001, figures to play at least one more season and is under contract for two seasons. And Hartings' backup and expected replacement, Chukky Okobi, agreed to a $10 million, four-year contract earlier his year.

Still, Philip played at a higher level than most sixth-round draft picks — he was an All-American at Cal — and he gave the Steelers some insurance in case something happened to either Hartings or Okobi.

That something happened Wednesday, when Okobi had surgery to repair a herniated disk in his neck. He is expected to be able to play again — coach Bill Cowher was worried Tuesday the injury might be career-threatening — but probably not until midseason.

Because the starters rarely play extended stretches during the preseason, Philip now figures to see substantially more playing time in the four exhibition games than he might have expected.

"It doesn't change the way I focus and the way I prepare myself, because I've got a chip on my shoulder and I'm out here to do the best I can," Philip said Wednesday. "There are a lot of doubters, a lot of people who say I'm too small or not strong enough to play in the NFL. I thought I'd be able to go higher (in the draft), but it worked out perfectly. I'm here and I'm ready to go."

At 6-foot-1, he is a couple of inches smaller than many NFL linemen, and it may have been one reason Philip fell to the sixth round. But, at 24, he is older than most NFL rookies and, he thinks, more focused than many players coming out of college.

"The maturity definitely helps in learning the offense and in being disciplined in a lot of areas," he said.

No doubt that AFC Central rival Cleveland wishes it had the Steelers' depth at center. The Browns have lost their top two centers, LeCharles Bentley (knee injury) and Bob Hallen (left camp) since camp began.

Philip sat out two seasons at Cal to go on a Mormon mission and thus came into the league several years older than most rookies. Steelers backup defensive lineman Chris Hoke also went on a mission while at Brigham Young and, despite being undrafted out of college, has stayed in the league since 2001.

"It's unfortunate that Chukky went down, but I'm ready. That's what I've been here to do, to go out and prepare myself to play," Philip said. "I think I've made strides."