Graham Potter says Reece James is "in a good place" again after the "brutal" experience of missing England's World Cup campaign.
Full-back James was left out of Gareth Southgate's 26-man squad for Qatar 2022, where England lost to France in the quarter-finals, due to a knee injury.
The 23-year-old has not played since sustaining the injury against Milan on October 11, but he returned to training at the start of December.
Potter acknowledged it has been a difficult period for James, who is set to feature against Bournemouth on Tuesday as Chelsea make their return to Premier League action.
"It was a World Cup and they come around every four years. So when you’re young, the perspective is not so easy to get," Potter said.
"You are young and you want to play. That's really understandable. It's the same for Reece, Ben Chilwell, N'Golo Kante. It's brutal really to have to deal with.
"You can try to help them and give them a bit of perspective but in the end it has to come from them, their families and those people close to them.
"I have to say he is in a good mood, he is in a good place. He has trained with us, is training well and is a good team-mate. He has dealt with it well.
"There is not too much you can say. You say it will get better with time and you have to focus on the things you can control.
"There is nothing you can say to a player that will make it get better. All I can do is acknowledge it is upsetting, that whatever he is feeling is normal and help him move forwards.
"It was a challenging period for all the players. There were another 12 that are watching their team-mates and getting injured and missing the World Cup.
"You have to think on some level there is an effect there. They're only human."
it’s been a while but back like we never left! pic.twitter.com/8v2IjJ0DIW— Reece James (@ReeceJames) December 15, 2022
Potter confirmed he will continue to monitor James' playing time, though Wesley Fofana and Chilwell remain absent, while key midfield man Kante is out until February.
James has started half of Chelsea's 20 Premier League and Champions League games this season, with his absence from the side coinciding with a downturn in results.
"He's been training for a few weeks now and that helps," Potter added. "The tough time is when you can't play football because you're injured.
"For him, the best thing is that he is playing football and the World Cup is finished now and he can concentrate on playing football.
"He was in a really good place before he got injured. If you look at how the team was functioning before he got injured and after.
"It's not the only reason of course but Reece is a top, top player and when he is not with us it's a miss.
"I'm confident the more football he plays the more we will see what a fantastic footballer he really is."