Colts put rookie RB Hart on IR; Addai limping

INDIANAPOLIS -- The Indianapolis Colts needed help in their injury-depleted backfield.

They expect three new running backs to fill the holes.

With Pro Bowler Joseph Addai unlikely to play Sunday against Green Bay, and Mike Hart out for the rest of the season, the Colts added three running backs to the roster Wednesday.

The Colts thought they addressed their most pressing need -- a leaky run defense -- with the trade for John McCargo, but a failed physical voided the deal. Then Sunday's injuries to Addai and Hart changed their priorities.

Addai left in the first quarter against Baltimore with a hamstring injury, and Hart, a sixth-round pick who was Michigan's career rushing leader, hurt his right knee in the second quarter. Coach Tony Dungy said Wednesday that Hart had been placed on injured reserve with an injured anterior cruciate ligament, though Dungy wasn't sure it was torn.

The only other running back on the Colts' active roster was veteran Dominic Rhodes.

"I don't know if he (Hart) will have surgery or not," Dungy said. "It's really, really a shame. He's a good player who brought a lot of energy. We think Chad Simpson can do that, too."

Simpson, an undrafted rookie from Morgan State, was promoted from the practice squad.

Addai's injury isn't nearly as serious as Hart's.

Dungy described it as a tweaked hamstring, but that may be enough to keep him on the bench this weekend.

"I wouldn't look for Joe to play this week, I think Dominic will start," Dungy said. "But I don't think it's going to be very long. I suspect that by the end of the week, there might be some thought of playing him, but my sense is we'll go with three guys."

That would be Rhodes, the former 1,000-yard runner who helped Indy win the Super Bowl in 2006, Simpson, the fastest and shiftiest back on the roster, and Clifton Dawson, who played with the Colts last season before being cut in August.

Besides promoting Simpson, the Colts signed rookie Lance Ball to the practice squad and re-signed Dawson, who spent the past seven weeks working out in hopes of getting a phone call.