INDIANAPOLIS -- More top quarterbacks than usual will throw pa ses at this year's NFL , but at least one intriguing talent at the position will sit out the drills.Colorado State's , who was available in the draft by NFL Media analyst Daniel Jeremiah, will have to wait until the ' pro day event to work out.Grayson has injured his hamstring, of USA Today.The draft's top Jalen Graham Jersey two quarterbacks, Florida State's and Oregon's , to throw this week. UCLA's and Baylor's will throw as well, making for heavy participation at Lucas Oil Stadium, where the combine often sees top quarterbacks sit out the pa sing portion of drill work.Grayson had a chance to show off his arm to NFL coaches and scouts last month at the in Mobile, Ala., where he was one of six quarterbacks to practice for a week in front of representatives from all 32 clubs.It's a thin draft at the position after Winston and Mariota. NFL Media's Mike Mayock has , and there are concerns about Petty's ability to transition from a hurry-up, shotgun offense to a pro-style attack.*Follow Chase Goodbread on Twitter *. Alex Barrett Jersey