The Premier League champions kick-started their trip to the Far East by beating a Thai All-Stars team 1-0 on Saturday.
However, there was some concern among Chelsea fans when Costa, who only came on at half-time, was forced to leave the field 20 minutes from the end of the game.
Mourinho, though, later explained that the Spain forward was taken off as a precaution after suffering from fatigue, as opposed to having a recurrence of the hamstring problems which plagued him last season.
???Because we had so many players injured and in surgery we asked Diego to come and try to play, which he did for 25 minutes,??? Mourinho said after the match.
???After that he was feeling tired so we had to protect him. He wanted to come, he respects the fans and he tried to play.???
Chelsea???s winner came after just 13 minutes thanks to a calm finish by Daniel Solanke, with Mourinho pleased with how his young players performed.
???I’m happy with them,??? he said. ???What I tried to do was play some of the more experienced players at the same time to give support to the boys.
???In the first half I played Cech, Ivanovic, Mikel and Remy , and in the second I played, Terry , Hazard, Diego Costa, Matic and Azpilicueta.
???For them it was a fantastic experience to play in front of a big crowd, it was very good for them.???