AUSTIN, Texas (AP) -- For a guy who has spent most of his career as a backup, Case McCoy carries himself with the swagger of a national championship-winning quarterback.
Whether it's leading Texas to an upset win over rival Oklahoma, or surrounded by reporters during game-week interviews, McCoy eases his way through just about every situation.
''Confidence,'' coach Mack Brown said, ''is not an issue.''
It's that swashbuckler's attitude has allowed McCoy to step in for injured David Ash and lead the Longhorns to three consecutive victories. Texas (4-2, 3-0) plays at TCU (3-4, 1-3) on Saturday.
The win over Oklahoma was arguably the brightest moment for a player who has struggled tried to live up to legacy of older brother Colt, the quarterback from 2006-2009 who led Texas the 2009 Big 12 title and the national championship game.
After spending his freshman season as the backup to Garrett Gilbert, Case McCoy briefly earned the starter's job as a sophomore in 2011 before quickly losing it to Ash. Even with a mad scramble to set up the winning field goal against Texas A&M that season, McCoy couldn't keep the starting job.
McCoy was stuck at No. 2 and while his teammates spent last summer working out in Austin, McCoy went to Peru on a 10-week mission to install water filtration systems to serve a remote village. Then Ash got suffered a head injury Sept. 7 against BYU and has played only one half of football since.
But even after the biggest win of his career, McCoy still faces doubters. Texas started the week as an early underdog against a Horned Frogs team that has struggled all season.
''Probably because I'm the quarterback, right?'' McCoy joked.
McCoy has certainly had his share of critics among Texas fans. Some assumed he rode into Austin on his brother's legacy. They criticized his average arm strength and penchant for turnovers. There were rumors early in his career that he would transfer. He denies that he considered leaving.
''No one thinks I'm any good except for my team,'' McCoy said.
McCoy is used to playing the role of underdog. As a child, he was afflicted with a rare form of scleroderma, a disease that hardens and tightens skin and connective tissues, and he battled its effects for nearly a decade. The result is still visible on parts of the left side of his body, from this face to his leg.
Offensive coordinator Major Applewhite, a former Longhorns quarterback, can sense the chip on McCoy's shoulder to prove he can deliver the top-level quarterback play Texas hasn't had since his brother was on the roster.
''The little brother syndrome, or the backup quarterback syndrome, whatever you want to call it,'' Applewhite said. ''I see it every day.''
Brown said he's watched McCoy try to make the plays his brother did. Sometimes it worked. Just as often it didn't.
McCoy threw a pair of touchdown passes against Oklahoma. He also misfired on a screen pass that was returned for a touchdown, and missed two more open throws that likely would have scored.
Brown had to reign in McCoy late in the game against the Sooners. The coach ordered him to run the plays called in from the sideline and not to try to change the play for something else, looking for a big-strike touchdown.
That didn't bother McCoy a bit.
''That was him being smart,'' McCoy said.