STATE COLLEGE — This would-be tackler tried to sneak in on Bill Belton’s blindside to swat away a ball tucked tightly inside the tailback’s arms.

No luck getting a fumble in Penn State practice for coach-turned-part time-linebacker Bill O’Brien — and that’s a good thing in the mind of the Nittany Lions’ new leader.

Toughness on the field won’t necessarily be measured by how the Nittany Lions bounce back from a turbulent offseason.

“It will be the ability to stop the run. It will be the ability to run the ball, and it will be our coverage teams, our kickoff cover, our punt cover, our ability to get down there and make the tackle, create turnovers,” O’Brien said at the team’s recent media day.

“So unity will have a lot to do with that. But at the end of the day, we’ve got to go out and execute and play good football.”

If that sounds familiar, it’s because O’Brien’s ousted predecessor — Hall of Famer Joe Paterno — often referred to the same three tasks in outlining his recipe for success.

But the child sex abuse scandal involving retired defensive coordinator Jerry Sandusky turned one of the country’s most well-known programs upside-down. The NCAA imposed landmark sanctions including a four-year postseason ban, and nine players took advantage of an NCAA waiver to seek immediate transfers to other schools in light of the penalties.

The goal is to still to win every game, even if a trip to a warm locale for a January bowl is no longer an option.

In terms of roster defections, though, the worst appears to be over for now. O’Brien wished those departing players well, but he’s more than eager to concentrate on the guys who stayed.

“The next guy steps up, the next guy is ready to go,” O’Brien said. “It’s your chance to shine.”

Enter Belton, the likely replacement for star tailback Silas Redd, who transferred to Southern California. Redd was a 1,200-yard rusher who figured to be a centerpiece of O’Brien’s revamped offense.

Recruited as a receiver, O’Brien converted Belton to running back this spring after being impressed with his balance and muscular, compact 5-foot-10 frame. Belton was also a standout run-pass quarterback threat in high school in New Jersey.

Belton did see time late last season in the backfield in the wildcat, but this would be his first experience as a full-time running back. He’s a quick study — an 80-yard touchdown run in practice a couple days ago really impressed O’Brien.

“Other guys will play,” O’Brien said in a conference call yesterday, “but Billy will start.”

Any semblance of a productive running game will help veteran quarterback Matt McGloin as he gets the new playbook down pat — the one that O’Brien modeled after the scheme he oversaw as the offensive coordinator for the pass-happy New England Patriots.

But instead of Rob Gronkowski and Aaron Hernandez at tight end, McGloin will be throwing to Garry Gilliam, a junior coming back from a left knee injury. Instead of steady receiver Wes Welker roaming across the middle, a group of relatively untested underclassmen will be counted on to catch passes from McGloin. It could even be a different look at tight end — though O’Brien cautions against making direct comparisons to how he used the position in New England.

“We’re not asking our tight ends at Penn State to be Rob Gronkowski and Aaron Hernandez,” he said. “We’re just asking them to block well and understand their assignments.”

Junior Shawney Kersey and sophomores Allen Robinson and Alex Kenney could be the new nucleus of a receiving corps that lost Justin Brown (transfer to Oklahoma) and Devon Smith (off-the-field issues) in the offseason.

Center Matt Stankiewitch is the only returning starter on the offensive line. Redshirt freshman Donovan Smith has been sidelined by a hamstring injury in preseason, but O’Brien hoped to get the promising 6-foot-5 left tackle back on the field this week.

“I’m not going to sit here and tell you that we’re going to go 12-0,” McGloin said. “But I can promise you that we’re going to be in each and every game, and have the opportunity to be in each and every game.”

To do that, Penn State will likely need another strong showing from its defense. Linebacker U. has reloaded at its premier position, even with the loss of top backup Khairi Fortt, who transferred to California.

Gerald Hodges could be an athletic force at one of the outside linebacker spots, while Mike Mauti is the hard-nosed team leader on the opposite side. Middle linebacker Glenn Carson is back in the middle for a second straight year, hoping that standout defensive tackle Jordan Hill in front of him can funnel ball-carriers his way for losses.

“You have a lot of guys that we can play, a lot of guys up front,” O’Brien said. “So I feel that is really the strength of our football team. With the linebackers, the front seven is the strength of our football team.”

New defensive coordinator Ted Roof wants to tweak Penn State’s successful schemes to raise the tempo a notch and offer different looks. More blitzing could mean more pressure on a new-look secondary that’s thin in experienced depth after backup cornerbacks Derrick Thomas and Curtis Drake also left for off-field reasons.

Two men will have to replace punter-kicker Anthony Fera after one of the Big Ten’s top specialists transferred to Texas. Sophomore Sam Ficken appears to have locked up the kicking job, though Alex Butterworth and Matt Marcincin are competing to take over the punting duties.

One of O’Brien’s toughest decisions in the coming weeks may be what to do with his freshmen. First-year players who typically may be candidates to redshirt may be needed this year to help fill depth at certain positions given the transfers.

The NCAA waiver gives players the ability to transfer at any time this year — provided they don’t play a game for Penn State. Players that get on the field on game days for O’Brien wouldn’t be able to transfer until after the season, when the NCAA transfer allowance would pick up again until the start of the 2013 preseason.

O’Brien yesterday said whether he plays all his scholarship players would depend on the flow of the game and the season. “We’ve got to do what we can to win the game,” he said.

It won’t be until about Week 4 when O’Brien plans to decide on redshirt candidates. In a best case scenario, it appears he’d rather not just have freshmen play bit roles from the bench.

“If you’re going to play a freshman,” he said, “you really need to play them.”