Jose Mourinho's men were practising their rookie diving techniques when team-mate Smalling took to Twitter earlier to joke about the dark art of diving in the modern game.
The video features himself, Shaw and Herrera diving from about the 5m platform into a swimming pool with the caption: 'Diving in the modern game is a disgrace!', alongisde a laughing emoji.
Diving in the modern game is a disgrace! @LukeShaw23 @AnderHerrera #MUFC #GGMU #ManUtd pic.twitter.com/9rWZWRKHFo
— Chris Smalling (@ChrisSmalling) 10 January 2018
The Manchester club are maintaining their fitness levels in the Middle East ahead of their fixture with Stoke at home on Monday night.
Although they are far off the leader's pace, the fight for the Champions League places is heating up. Antonio Conte's Chelsea lie only one point adrift, while Jurgen Klopp's Liverpool are just three points behind with 16 matches remaining in the league.