The Indianapolis Colts enter the regular season far from injury-free at running back, but general manager Ryan Grigson said Wednesday the team isn't concerned.

"We feel great about our running back group -- great," Grigson said, per ESPN's Mike Wells.

The Colts, who only a week ago appeared to have a surplus at the position behind starter Frank Gore, are now dealing with injuries to a number of backups. Vick Ballard made the roster despite suffering his third hamstring strain of the summer in the preseason finale against the Cincinnati Bengals. Another key reserve, Daniel "Boom" Herron, hurt his shoulder in the that game and was waived/injured before reverting to the team's injured reserve. Finally, rookie Josh Robinson, is recovering from a concussion.

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Fortunately for the Colts, Robinson, a sixth-round pick out of Mississippi State, passed the league's concussion protocol and has returned to practice. He and undrafted free agent Tyler Varga are likely to see carries behind Gore on Sunday against the Buffalo Bills.

"Just knows how to run," Grigson said of Robinson. "He knows how to carry the football. He's got things he's got to work on, but we want guys that are trending towards being starters."

Ballard hasn't appeared in a regular-season game since Week 1 of the 2013 season, but Grigson said the veteran was too talented to cut.

"He's a talented guy," Grigson said. "Like we said, he's done a lot of great things here and you saw glimpses of that. You're going to pump the breaks before you let someone with that talent just walk out your door. He's had some minor dings. They're not majors. We'll just take it day by day with him like [with] all these guys."

(h/t ESPN)