His teammates call him “Xbox.”

That’s not only because Josh LeRibeus is widely acknowledged as the Washington Redskins’ best video gamer. It’s also because of the implied 360, as in Xbox 360, which only slightly exaggerates the weight the former Southern Methodist guard ballooned to at his heaviest.

Reporting for spring workouts roughly 30 pounds overweight last year, LeRibeus squandered any chance of competing for a starting job and was relegated to the inactive list the entire season, too out of shape to do any good.

“Just immature,” said the 6-foot-2 LeRibeus, who is finally back to his rookie weight of 315, in explaining what led him to slack off at the gym and indulge his late-night yen for Mexican food once back in Texas after his rookie season. “I started out the first couple weeks working out, then took a day or two off, figuring I’d do it the next day. You start pushing it back further and further, and it bites you in the butt.”

That said, LeRibeus is among the fortunate ones given a second chance in the NFL. For that, he has two factors to thank:

The Post Sports Live crew explains why no major news out of training camp is good for the Redskins coming off of a 3-13 season. (Post Sports Live/The Washington Post)

• The Redskins badly need help bolstering their offensive line if quarterback Robert Griffin III is to have any chance of exploiting the offensive weapons arrayed around him this season — three-time Pro Bowl wide receiver DeSean Jackson, Pierre Garcon and Andre Roberts, among them.

• As a third-round pick in the 2012 draft, LeRibeus would represent a costly blunder by the front office if his career in Washington amounted to nothing more than the five games he played as a rookie.

“They always tell you, ‘Try not to make the same mistake twice,’ ” LeRibeus said. “Well, I made the big mistake. And I’ve kind of got myself together in the offseason — working out, training, getting into a routine and come back with Ray Wright [the team’s strength and conditioning coach] to give myself a chance.”

But the job LeRibeus let slip through his grasp is hardly his for the taking.

The Redskins have 14 offensive linemen on their training camp roster for eight to 10 jobs. First-year Coach Jay Gruden appears to have his starting five set, anchored by the freakishly gifted Trent Williams at left tackle. Kory Lichtensteiger slides to center, fifth-year veteran Shawn Lauvao takes over at left guard and Chris Chester and Tyler Polumbus return on the right side.

But the backup slots are in play. And there’s a particular logjam at guard, with third-round draft pick Spencer Long, Mike McGlynn, Adam Gettis and Maurice Hurt in the mix with LeRibeus.

Gruden has taken note of the fact that LeRibeus took his offseason conditioning seriously this year, arriving for workouts at the proper weight and fitness level.

The Post Sports Live crew debates whether the Redskins new head coach is the opposite of their former head coach. (Post Sports Live/The Washington Post)

“We just need to see more consistent play from him,” Gruden said. “I think he’s trying to do the best he can. . . . We’ve got a lot of guys in there that can play the interior. We just need guys to step up and do it consistently to prove that they deserve to be here.”

For LeRibeus to distinguish himself, he’ll have to do far more than make weight.

Versatility counts, given that backup interior linemen are likely to be called on to plug holes on the right and left side — conceivably at center, too.

Consistency matters even more.

Said offensive line coach Chris Foerster: “Maintaining your weight is a consistency thing. It’s the same way with Josh’s game: One time it’s as good as you could ever ask a guy to do it; another time it’s not quite as good.

“That’s not necessarily a character flaw. It’s just a matter of working. Once you do things enough, it becomes a more consistent action or skill that you acquire. That’s where it is right now: Just consistency.”

LeRibeus knows that’s what he must prove this preseason to earn a spot on Gruden’s 53-man roster. And he knows it’s impossible to state his case in one practice or a single preseason game.

“I think it’s just something you’ve got to see over camp,” LeRibeus said. “They’ll judge that day by day. Little things you nitpick: Maybe your eyes need to be in a better spot. But other than that, it’s coming along well. Things are starting to click, and I’m enjoying myself.”

There’s a carefree quality about LeRibeus that’s not what you would expect. While other 300-pounders trudge on and off the field with grunts and growls, LeRibeus reports for duty as if a song is in his head. He laughs easily and often. He’s a magnet for autograph-seeking children, who teem around his knees after practice and stare in awe, as if they’ve just met the Jolly Burgundy Giant.

And he’s the type of teammate fellow players root for.

“I’m real proud of Josh,” said cornerback Richard Crawford, who played with LeRibeus at SMU. “He has lost the weight. He’s moving real well out there. He has come a long way, and he has worked really hard to get to where he’s at.”

Adds Williams, the Redskins’ two-time Pro Bowl lineman: “He came back in great shape, way stronger. You can just tell he busted his butt this offseason.”

A “gentle giant” off the field, according to Crawford, LeRibeus is fully capable of unleashing the requisite intensity when taking on 320-pound defensive linemen.

“He brings another nastiness to the offensive line when he’s on the field,” Crawford said.

Foerster appreciates the guard’s duality. LeRibeus has a great temperament in meetings — even keeled and unflappable. “He’s the same person every day, and you respect that,” Foerster said. “Now if we could just get him to play the same every day.”