MELBOURNE's high performance team has been raided by the AFL's umpiring department, with strength and conditioning manager Rob Jackson leaving to take charge of the AFL umpires' fitness program.

Jackson, who was the second in charge to elite performance manager Dave Misson at the Demons, will join the AFL umpiring team that recently appointed Grant Williams as its boss. 

The Demons' staff and players were told of his departure on Monday morning.

Jackson joined Melbourne alongside Misson in 2012 following a two-year stint with the fitness guru under Ross Lyon at St Kilda.

He also previously worked at NRL club Melbourne Storm. 

James McGeoch was in charge of the Melbourne players' gym programs on their recent pre-season training camp in Maroochydore and could step up his responsibilities.

Alex Sakadjian is the club's sports science co-ordinator and rehabilitation coach, and plays a key role in working with injured players.

Former Western Bulldog and Demons player Daniel Cross has a strong reputation in his role as development and rehabilitation coach, but has only been in that position since the end of 2015 when his playing career ended.