This decision has been made by manager Enzo Maresca, who has been pushing Sterling aside since his return from a loan spell with Arsenal last season. The move has been met with concern from former Premier League striker Gabby Agbonlahor, who spoke out about the potential impact on Sterling's mental health.

"Players felt like they couldn't speak to the group, that they didn't want to get caught talking to them," Agbonlahor said. "It makes you feel so low." He also noted that Sterling's treatment is not unique, citing other players who have been similarly ostracized when their clubs no longer wanted them.

Agnolabhor also pointed out Sterling's impressive career statistics, including 82 England caps, 20 goals, and four Premier League titles. Despite his past success, Sterling has been struggling to find his footing this season, and his situation is likely to be closely watched in the coming months.

With the January transfer window approaching, Sterling may soon have the opportunity to leave Chelsea and find a team that is a better fit for him. In the meantime, he will continue to train alone, a situation that is likely to have a significant impact on his mental health.

Sterling's situation serves as a reminder of the challenges that professional athletes can face when they are no longer wanted by their teams. It is a complex issue that requires a thoughtful and compassionate approach, and one that should be closely monitored in the coming months.