The Portuguese boss has guided the side to victories over LA Galaxy, Real Salt Lake, Manchester City and Real Madrid, with United losing to Barcelona in the last game in America.
Herrera and Mata had been previously ruled out and Mourinho had confirmed that they were back to get ready and pick up sharpness ahead of the new season.
Speaking prior to the game, Mourinho confirmed his change in tactics.
“The result is not the most important thing but we felt against Barcelona we were not happy with defeat, so we are going to try and win,” he said.
“We are going to play four at the back in the first-half and three at the back in second-half.
“Mata didn’t have a pre-season, Ander didn’t play in the last two, so important for them to compete again.”
“Ander is the sort of player who needs his rhythm back.”
Man United’s focus will be on facing Real Madrid in the UEFA Super Cup Final on August 8 and there’s plenty to get on with between now and then as Ed Woodward also looks to bring in Nemanja Matic and Ivan Perisic ahead of the new campaign.