View Photo Gallery: Heisman Trophy winner Robert Griffin III is a highly coveted prospect heading into the 2012 NFL draft.

Indianapolis Colts owner Jim Irsay says Baylor quarterback Robert Griffin III, through his agent, declined a request for a private workout.

The Colts hold the top pick in the NFL draft and have long been expected to take Stanford passer Andrew Luck. But Irsay said the Colts, who are holding a private workout with Luck today, wanted to do their due diligence and work out Griffin as well.

Irsay tweeted today that Griffin didn’t want to do so, however.

“A Luck private workout 2day..we want 2b as thorough n disciplined n process of #1 pick..we wanted 2do private with RG3,but his agent said no,” Irsay tweeted Tuesday morning.

Griffin met with members of the Washington Redskins brass last month when coach Mike Shanahan, owner Dan Snyder, general manager Bruce Allen and offensive coordinator Kyle Shanahan attended his pro day in Waco, Tex. He also has a visit scheduled with the Redskins later this month, according to a person with knowledge of the situation.

It’s unclear if his declining the Indianapolis invitation means he’s resigned to going second overall to the Redskins, or if he would rather play for Washington instead.

Griffin’s agent, Ben Dogra, didn’t respond to requests seeking comment.

Griffin this past weekend was in Chantilly, signing autographs at a sports memorabilia show, but did not meet with the Redskins during that short trip to the area.