STILLWATER, Okla. — No matter who’s at quarterback, the offense has chugged right along this season for No. 22 Oklahoma State.

The engineer these days is Clint “Choo Choo” Chelf, the third-stringer who has gone from practically unknown to cult hero in a matter of weeks.

Once forgotten at the bottom of the depth chart, Chelf was thrust into the starter’s role after Wes Lunt and J.W. Walsh both got hurt. After back-to-back wins in the first two starts of his career, Chelf is the starter after coach Mike Gundy spent the past two months trying to keep it a secret who’d take the snaps from game to game.

“Whatever train he’s driving, I’m getting on,” Gundy said Monday.

The “Choo Choo” Chelf concept was sparked by a profanity-laced Internet post that was jokingly attributed to him leading up to OSU’s game against West Virginia two weeks ago. With uncertainty over whether Lunt would be able to play, the possibility arose that Chelf would finally get a real chance after backing up first-round NFL draft pick Brandon Weeden the past two seasons.

A Chelf-related hashtag trended on Twitter as he threw for 292 yards and four touchdowns in the win over the Mountaineers, and center Evan Epstein only encouraged it after the game with his tweet: “All Aboard!”

“I think it’s hilarious,” Chelf said. “I think it’s great any time they can take something and run with it. It just happens to be about me, I guess. I think it’s funny.”

Making it all the more comical is that the boisterous, all-caps expletive rant couldn’t be more different from Chelf’s actual mild-mannered, unassuming personality. When asked if he was looking forward to starting in the Bedlam game, Chelf answered simply: “Absolutely.”

No bragging about OSU’s potential to win back-to-back games in the series. No trash talk.

“He’s not a guy that’s going to be running in there head-butting guys like a train ... pumping his fist,” defensive end Cooper Bassett said. “He’s more like a quiet competitor, and he’ll celebrate with his teammates, but he very rarely tries to get the attention on himself, which is the sign of a great leader and a great competitor.”

Gundy said part of his rationale in naming Chelf the starter at this point is the groundswell of support for him not just in public, but on the team.

“I think the guys are behind him,” Gundy said.

Chelf’s story is one of perseverance. His only chances to play during the past couple seasons were in garbage time, taking meaningless snaps after Weeden and the first-teamers had victory well in hand.

He finished third in the three-way competition with the freshman Lunt and redshirt freshman Walsh in the spring, and there didn’t seem to be a light at the end of his tunnel. Yet, the junior didn’t quit or transfer somewhere else where he’d be more assured of playing time.

“For me, I don’t really feel like it’s any type of feel-good story. There’s a lot of stories around college football that are a lot more exciting and better than mine,” Chelf said. “I just was a player that got beat out and stuck with it and got a chance. I’m happy that it happened.”

Chelf grew up in a divided household in Enid, about an hour’s drive west of the OSU campus in north-central Oklahoma. His mother’s family supported the Sooners, his dad’s side the Cowboys and he attended games at both stadiums.

As he was getting recruited by OSU in high school, he really started to pick sides. His older brother, Colton, also walked on as a wide receiver for the Cowboys.

Now, he’ll be the one in the spotlight when Bedlam rolls around.

“Any time that you can get on a stage like that and perform well, you want to do it. There’s a lot of times when I said, ‘I hope that can be me some day,’” Chelf said.

With all the sudden attention, Chelf said he’s not the big man on campus — perhaps because he’s nearing graduation and only has one class a day, with the rest online. With social media, though, his stardom is well-known.

“I saw it on Twitter and it just kind of blew up after that,” receiver Isaiah Anderson said. “I’ve seen people with conductor hats on and train whistles.  It’s ridiculous, but I’m happy that he’s kind of getting out there like that, and I’m pretty sure he’s enjoying it too.”

At practice, his teammates will yell “choo choo” at him and Bassett even caught himself celebrating a Cowboys touchdown pass by pumping his fist as though he were pulling on a train whistle.

“It’s really taken off. It’s only about a week old, but he’s already got shirts made for him,” guard Lane Taylor said. “It’s crazy. I’ve never seen anything take off like this before.”

Bizarre as it may be, the Cowboys just hope Chelf doesn’t get derailed any time soon.

“If that makes him play better, then I’m all for it, because he’s done a great job being known as the Clint Chelf ‘Choo Choo’ Train,” Bassett said. “So, we’ll ride that train the rest of the season, and hopefully it’ll carry us to a few more wins.”