INDIANAPOLIS — On his first snap in an NFL game, Hugh Thornton sprinted around the left side of the Indianapolis Colts' offensive line.
Pulling from his right guard position, he was looking for an outside linebacker attempting to set the edge. Sixth-year linebacker Quentin Groves of the Cleveland Browns popped into the open field to oblige.
Thornton, a rookie out of Illinois who missed most of training camp with an ankle injury, thundered into Groves. First he stood the veteran up, stalling his progress. Then he forcefully drove Groves to the ground away from the play.
In that moment, Colts fans got a glimpse of the future.
Offensive coordinator Pep Hamilton considers his linemen to be "skill" players, especially the guards who are routinely asked to pull. He values the kind of athleticism Thornton showed in quickly getting to Groves during Saturday's exhibition victory. And he demands the physicality Thornton delivered to finish his block.
How quickly the future arrives still is in question. But there's no doubt Thornton commanded attention in his debut.
"If you go back and watch the tape, it's pretty impressive what he did on his very first snap out there," head coach Chuck Pagano said. "Again, he played consistent football throughout. He was good in the run game. Got tied up on one pull, ended up on the ground, but other than that, run and pass he did a nice job."
With Mike McGlynn still on the mend with a bone bruise, Thornton will start at right guard Thursday when the Colts finish the preseason in Cincinnati. Unlike many of the other starters, however, Thornton isn't likely to be removed after a series or two.
His ankle was rolled into during the Colts' final mini-camp practice in June. He reported to training camp at Anderson University in late July wearing a boot and watched from the sidelines throughout the team's three-week stay.
He returned to practice just last week and made his pro debut four days later. Rather than pity himself during the injury, Thornton used the down time to improve.
"I think I had to learn how to become more professional and take some mental reps and change the way I studied film and just looked at the game," he said. "When I came back, I made some mistakes. They were easy to correct. The guys were helping me out throughout the whole game."
Now that he's back on the field, Thornton wants to make his playing time just as productive.
His lack of training camp practices robbed him of some conditioning time, and he said he must improve his recognition of defensive tricks such as line stunts. He's also working on his chemistry with his teammates and becoming more comfortable with his role.
That might seem like a lot to accomplish with the regular-season opener looming Sept. 8. But Thornton already has made up a lot of ground.
The third-round pick saw playing time with the first unit against the Browns — even though veteran Jeff Linkenbach got the start in place of McGlynn — and seemed to make the most of it.
"I would have been happy wherever they put me," Thornton said. "I'm just glad to be out there playing football again after coming here with high expectations for myself and for the team. And just being able to be with that group and the group trust me enough to help out and play with me, it was an awesome feeling."
Whatever chance Thornton had to compete with McGlynn for the starting job likely was erased by his training camp absence. But McGlynn's own injury has again opened the door a crack.
Thornton likely will get another extended audition against the Bengals, and if all goes well he'd be the first in line if McGlynn's recovery unexpectedly lasts past the regular-season opener against Oakland.
No matter his role, Thornton will prepare for any eventuality. If the 6-foot-3, 334-pounder has learned anything in his brief NFL career, it's that everything can change — for better or worse — on a single snap.
"That's the way it goes in football," Thornton said. "It's unfortunate. I've been there. Other people have been there as well. When the opportunity comes, you got to take it. You got to run with it and do your best to help the team as a unit."