Texas coach Steve Sarkisian served a reality check to quarterback Arch Manning after his uneven play in the Longhorns’ 27-10 win over UTEP on Saturday at DKR-Texas Memorial Stadium in Austin, Texas.The 51-year-old coach said the sophomore quarterback appeared to drift away from the Longhorns’ playbook and lean too heavily on improvisation. That prompted Sarkisian to share his concerns about the preseason Heisman Trophy favorite."I'd let him run around and start playing football. But I feel like he pressed some tonight. He's missing some throws that I feel he's comfortable making," Sarkisian said in his postgame news conference."You start skipping reads, relying on his legs too much. And that's always my caution. When you have a little success with your legs, you start to rely on your legs and then we're out of scheme and just play athlete football," he added. "And athlete football can get you so far, sooner or later that catches up on you too. We've got to get back into believing into the scheme."Sarkisian said Manning’s struggles are mental and stressed the need for him to refocus after mistakes.The sophomore carried the ball nine times for 51 yards and two rushing touchdowns. But Sarkisian felt Manning’s reliance on the run contributed to his passing struggles, as he went 11-of-25 for 114 yards with one touchdown and one interception.Texas' defensive line stops UTEP's rushers to ease Arch Manning's poor gameThe Texas defensive line clamped down on UTEP’s rushing attack and forced quarterback Malachi Nelson to throw downfield. The Longhorns limited the Miners to 50 rushing yards on 23 attempts, pushing Nelson to rely more on his arm.Texas was prepared, intercepting him twice and holding him to 209 passing yards -- a steep drop from his 278-yard, four-touchdown performance in UTEP’s 42-17 win over UT Martin.The Longhorns’ defensive front also stopped UTEP on 11 of 15 third-down attempts and denied three fourth-down tries in a dominant effort.Texas hopes Manning will bounce back from his struggles when the Longhorns host Sam Houston State on Saturday, Sept. 20.