PLAYERS temporarily substituted for a concussion assessment may be able to return to the field after 20 minutes of real time rather than waiting for 20 minutes of game time to pass.

The proposal to the AFL has come from club doctors.

Under existing concussion rules a player subbed for assessment with five minutes to go to half-time cannot return to the ground if given the all clear until the 15-minutes mark of the third quarter.

However club doctors would like to see breaks after each quarter included as part of the 20-minute assessment time.

AFL Medical Officers Association representatives put the proposal to the AFL recently and AFL.com.au understands the AFL is yet to consider its implications in full.

The AFL has tightened rules around concussion for 2015.

The new system will ensure that doctors examine all players who receive a knock mid-game, with trainers expected to inform doctors if they see a player injured.

The League has also moved to create a list of symptoms that will automatically rule players out of games.

Such moves are likely to see more players assessed for signs of concussion during games, with 20 minutes of real time considered sufficient to make the assessment.

The AFL has made responded in recent seasons to concerns about potential long-term effects of concussion, introducing rule changes to protect the head, concussion substitutes, a standard concussion assessment tool, and the use of broadcast footage to assess impact and research.