AFL football operations manager Adrian Anderson has announced a multi-skilling trial whereby goal and boundary umpires will be able to award matter of fact free kicks during the round one NAB Cup match between Melbourne and Hawthorn at Telstra Dome on Sunday.The goal and boundary umpires will be empowered to award free kicks such as push in the back, high contact, incorrect disposal and holding the man which have not been picked up by the field umpire.This trial has previously been conducted in NAB Challenge matches in previous years.Also, the AFL Umpiring Department would be trialling nine rookies through the pre-season, with one position available on the senior AFL umpiring list for the season.Four field umpires will officiate in each NAB Cup game, as distinct from three in the regular season, as part of a trial that was begun last season, while the load on boundary umpires will be reduced with the trial of a three-boundary umpire system."The NAB Cup and the NAB Challenge allow us to trial things that may benefit our game going forward and we will look at a number of young umpires who are bidding for senior AFL spots," Anderson said."The AFL Umpiring Department will also be trialling a few on-field differences to see what benefits may come out of further examination of a multi-skilling trial, and reducing the load on boundary umpires," he said.Separately, the following guidelines would again apply for any and all matches that may be affected by heat in the early part of the season.Current Alerations to Normal Match Rules* All teams to play with 24 players, as against 22 players for the premiership season. (Note: squads can be expanded further to 26 players if heat or humidity conditions require, and this has already been done for matches to be played at Cairns and Darwin.)* All quarters to be shortened to 17.5 minutes, plus time-on, as against 20 minutes, plus time-on, for the premiership season.* The allowance for expansion of club player lists with rookie list players allowed to play in all NAB Cup and NAB Challenge matches.Possible further Alterations to Normal Match Rules* The capacity for half-time intervals to be extended from 20 minutes to 25 minutes. (Note, this has already been done for matches to be played at Cairns and Darwin).* The capacity for teams to leave the field during quarter breaks.* Provision of at-match cool rooms, fans and player ice-vests as required at any and all venues.* Provision for extra water boy / fitness staff as required at any and all venues.Anderson said the AFL continued to work with clubs and the Medical Officers' Association to ensure players were fully ready for the start to each season and said the level of professionalism around clubs in their preparation for a season was unmatched.