ANDERSON, Ind. (AP) -- Colts left guard Donald Thomas may have re-injured his right quad during Wednesday afternoon's practice. Thomas missed all but two games last season with a torn right quad.
A person close to the situation said the Colts are checking the right quad, though a full diagnosis has not yet been made.
The person spoke to The Associated Press on condition of anonymity because the Colts have not publicly disclosed details of the injury.
Thomas appeared to reinjure his right leg during a team drill as he ended up on the ground. The 6-foot-4, 303-pound Connecticut native quickly got up, then limped behind his teammates and tried to walk off the injury.
A few moments later, Thomas put both of his hands on top of his head.
The Colts remain hopeful Thomas, who also had offseason surgery to repair a torn biceps, will make it back to the field soon.
Thomas' return was expected to help solidify the Colts' offensive line, which used six different starting lineups in the final six regular-season games last year.
That wasn't the only scare for Indianapolis on Wednesday. Receiver T.Y. Hilton also missed the end of the afternoon practice after jamming a finger on his right hand. Tight end Dwayne Allen, who had a season-ending hip injury last year, cornerback Vontae Davis and safety LaRon Landry all sat out for precautionary reasons.
All five players were projected to start this season.
The Colts are already without running back Vick Ballard who is expected to undergo season-ending surgery on his torn left Achilles' tendon. Ballard led the Colts in rushing in 2012 and was trying to return from a torn ACL in his right knee that forced him to miss the last 15 games in 2013.
The Colts did have one notable return from the injury front: Running back Trent Richardson worked out in shoulder pads Wednesday for the first time since camp opened. He had not participated in any workouts since Friday.
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