The NFL is proposing an overhaul to its offseason calendar, pushing back the combine to early March, the start of free agency to early April and the draft to early May, according to league sources.

The plan must be approved by the NFL Players Association, but the league already is pushing it aggressively, meeting on the issue most recently -- but not exclusively -- Thursday night in Indianapolis, where the NFL scouting combine is being held.

Under the proposal, all NFL teams also would kick off training camp on the same summer day, making it the official launch of the football season.

The idea is to lengthen the NFL offseason and make sure football is relevant during a longer offseason period with one big event in each month. It also would create a new revenue stream for the NFL, with each event producing added money for the league.

The NFL also wants to expand regional combines as a feeder competition for spots at the official combine in Indianapolis.