ARLINGTON, Texas (AP) -- Clint Chelf remained confident that his senior year at Oklahoma State would not end with him standing on the sidelines, and he was right.
When the No. 13 Cowboys (10-2, 7-2 Big 12) take the field at AT&T Stadium Friday night in the Cotton Bowl, Chelf will be guiding the OSU offense against No. 9 Missouri (11-2, 7-1 SEC).
Pulled from Oklahoma State's season opener in the first quarter, Chelf spent the next several weeks as the backup, watching sophomore J.W. Walsh thrive as the squad's primary quarterback.
Through it all, Chelf never got down, supported Walsh as best he could, and worked as hard as ever in practice while continuing to prepare as if he were starting every week.
His hard work paid off when Walsh's inconsistency prompted OSU coach Mike Gundy to re-insert Chelf into the lineup midway through the Cowboys' 24-10 win over TCU on Oct. 19.
''My family's a great support system for me, and unfortunately for me, I've been through that before, so I knew exactly what I had to do,'' said Chelf, who started five games in 2012 while sharing playing time with Walsh and Wes Lunt. ''It's a tough game and hopefully, my opportunity would come. I just had a gut feeling that I'd get another chance and just to be ready to take advantage of it.''
Along the way, Chelf served as inspiration for his teammates and exemplified the impact that a committed, selfless player can have to his team's success.
''He practices hard no matter where he is on the depth chart,'' said senior receiver Charlie Moore. ''You never know (if the next opportunity is coming) and that's a testament to Clint's work ethic. He kept working hard and kept being a great teammate to J.W., just kept pushing, and everything ended up working out. I'm proud to see him end it on top, he deserves it.''
When Chelf finally got his chance to get back on the field, the Cowboys had just lost at West Virginia on Sept. 28 and barely squeaked past Kansas State on Oct. 5. His return to action didn't quite have a fairy tale beginning, though, as he threw an interception on his very first play.
Despite completing just 10 of 25 passes for 178 yards, Chelf did enough to help Oklahoma State secure the win. OSU went on to win the next five games as Chelf got better and better.
''He's done very well since we put him in,'' Gundy said. ''The first game or two was very average in several things, other than he was a very effective runner for us. For the most part, his passing got better as the season went along and he's been a good manager of the game for us. There were a few games there where the offense didn't look very good, but he was effective enough for us to win.''
Chelf's ability to run the ball, he has topped 80 yards rushing three times and scored five touchdowns, was particularly beneficial.
''It's fun to throw touchdown passes, but it's a totally different thing to run one in, especially from a long ways out,'' said Chelf, who scored a touchdown on the Cowboys' longest individual rush of the season, a 67-yard run at Texas Tech Nov. 2. ''That's exciting. It's something that I always thought I could do.''
Chelf's trajectory toward an All-Big 12 Second-Team selection culminated in a stunning 49-17 triumph over then-No. 3 Baylor on Nov. 23 in which he completed 19 of 25 passes for 370 yards and three touchdowns against the conference's top-rated defense.
That game put the Cowboys in position to claim their second Big 12 title in three years, but a devastating loss in the season finale on Dec. 7 against in-state rival Oklahoma allowed Baylor to emerge as Big 12 champions and earn the conference's BCS Fiesta Bowl slot.
Now, Chelf is determined to close out his college career on a high note.
''We're certainly motivated. This is the last game some of us are going to play here, so you obviously want to win,'' Chelf said. ''For all that we've been through as seniors, we all want to go out with a win. Have a fun bowl, enjoy it and take it all in. There have been ups and downs, and it's like that for everybody in every season, but I'm proud of the way we finished.''