INDIANAPOLIS – The Indianapolis Colts have gotten a lot of mileage out of Andrew Luck’s legs. Maybe too much.

Shaky protection has forced Luck to scramble all over the place and it wasn’t pretty again Sunday, with Indy down 20-7 to Tennessee at halftime after rushing for just 12 yards. By the time the game was over, rookie Vick Ballard had a season-high 94 yards rushing and the Colts had done enough to take some pressure off their star passer in a 27-23 win.

“Yeah, we struggled in the first half a couple of matchups,” Colts interim coach Bruce Arians said after the game. “Our coaches did a good job of finding some runs that we liked at halftime and Vick (Ballard) did a good job of picking and sliding and coming out of there.”

If only the Colts could run that way all the time. Indy’s running game is better than it was last year, but it has been inconsistent. The Colts (9-4) find themselves in position to make the playoffs, but it’s unlikely they’ll go far unless they improve their ground attack. Indianapolis ranks 22nd in the league in yards rushing per game, and Luck has been sacked 32 times this season.

For the run game to improve, the offensive line must get better and stay healthy.

Left tackle Winston Justice had a head injury two weeks ago against Detroit, then had a biceps injury against Tennessee. Center Samson Satele hurt his ankle against Tennessee. Both missed the second half. Left guard Joe Reitz missed the Tennessee game with a head injury. Arians said he won’t know where any of those players stand until at least Wednesday.

The hodgepodge left Luck scrambling all over the place in the first two quarters against Tennessee. He was sacked three times in the first half on Sunday and was pressured on most of his other throws.

“He got hit quite a few times in this ballgame,” Arians said Monday. “We’ve got to keep him cleaner.”

Rushing performances like the one in the second half will help.

Ballard, a rookie, leads the Colts with 562 yards rushing. He has stepped in because Donald Brown was out with an ankle injury.

Arians likes what Ballard has brought to the team.

“He’s powerful. He’s a poor man’s Edge (Edgerrin James),” Arians said. “He’s bowlegged like Edge and he’s about the same size and tough to bring down. He’s quick, he’s elusive, doesn’t have the great, great speed but he can make the first guy miss and he’s going to make a lot of yards because he makes people miss. He’s got a great future, stay healthy.”

Ballard hopes to be a part of the solution.

“Coming into rookie minicamps, I was just focused on trying to learn the plays and learn the offense,” he said. “A couple injuries happened to the backs ahead of me and that bumped me up. I just try and take advantage of my opportunities.”