The 19-year-old complained about a back injury during Chelsea's victory over Sydney FC on Tuesday, but Mourinho’s post-match comments suggested that he wasn’t convinced. He felt the player was making excuses for struggling when the Australian side had possession.
Mourinho believes his relationship with Loftus Cheek has taken a step back, although Terry feels his team-mate can learn from the incident and return stronger for pre-season and the upcoming campaign.
"He's a young boy and he needs to take it on the chin," Terry told reporters, as per Goal.
"If you want to get into this team you need to be very good and, secondly, you need to be mentally strong.
"The manager picks his times when he digs people out; that's part of his learning curve and he's got the offseason to think about that now.
"He's made a couple of games, come on a couple of times and started a couple of games late in the season, but for him to make that next step and become a regular, it doesn't happen easily. It's going to be hard work for him.
"We've all been there as players and you look for the people or friends around you, but more importantly it has to come from within him.
"He's a great boy, he's got unbelievable talent and he just needs to kick on now. I'm sure he will, but as captain I'll have a quiet word for sure."
This is a difficult situation for Loftus-Cheek. He is a youngster coming into the frame at Stamford Bridge, getting an opportunity here and there from Mourinho. If his claims were false about a back injury, the midfielder has a lot of hard work to do before regaining his manager's trust.
Terry's job as captain is to help Loftus-Cheek mentally and to make sure this does not affect his performances further. The former England captain has gone through a number of difficult moments in his career, many caused by himself, but has bounced back stronger.