Louis van Gaal considered having his Manchester United players train with virtual reality headsets.
The Daily Mail says the Dutchman was sacked in May, allowing the club to appoint Jose Mourinho, but had big plans should he have remained.
Virtual reality goggles are said to offer tactical and 'game play analysis' whereby players can review clips shot through their own eyes during matches.
United's stars could have paused footage on the goggles to take a 360 degree look at what was around them at specific junctures.
Developed by Beyond Sports, the technology is being used at PSV Eindhoven this season, with virtual reality footage pooled from 'already existing camera or tracking infrastructure'.