LOS ANGELES -- USC Trojans junior quarterback Matt Barkley has submitted paperwork to the NFL draft advisory board seeking its input on where he could be selected in next April's draft.

It's standard procedure for a draft-eligible junior. More than 150 players from across the country typically request evaluations each year. It also has been Barkley's plan for some time; he told ESPNLosAngeles.com earlier this month he would submit the paperwork soon after the season ended.

"Don't think too quickly. I think it's something that every top recruit, or potential draftee does before thinking about going out. It's just a kind of evaluation, I don't think it's even that detailed. Just listing a potential round that you'd go in," Barkley said on "SportsCenter" Wednesday night.

Along with Barkley, there are three other USC juniors contemplating entering the draft early: left tackle Matt Kalil, defensive end Nick Perry and safety T.J. McDonald. All three players have requested or plan to request the evaluation by the Dec. 17 deadline.

All draft-eligible players have until Jan. 15 to declare for the draft and until Jan. 18 to withdraw. The news of the official filing was first reported by the Los Angeles Times.

The evaluations eventually come back to the players -- well before the declaration deadline --- with a full-length report on their projected draft status. And they all receive round grades, or where those polled in the NFL foresee the given player going in the draft.