Mamadou Sarr has admitted that his final months at Chelsea were extremely difficult, revealing that he felt isolated before securing a summer loan move to Real Sociedad.

According to a report by Football London on Thursday, 5 November 2026, the Senegalese defender struggled for opportunities after making a costly mistake against Paris Saint-Germain in the Champions League.

Sarr returned to Chelsea from Strasbourg in early 2026 after Liam Rosenior brought him to Stamford Bridge. The 21-year-old initially featured regularly, making four starts, including appearances against Wrexham and Hull City in the FA Cup and Arsenal in the Premier League.

However, his involvement quickly diminished following Chelsea's Champions League meeting with PSG. With the Blues already trailing 5-2 on aggregate, Sarr failed to deal with a long ball early in the second leg, allowing Khvicha Kvaratskhelia to get through on goal.

The defender subsequently lost his place in the team and struggled to regain the confidence of the coaching staff. Rosenior's dismissal further complicated his situation.

Speaking to L'Equipe, Sarr described the experience as a difficult period in his career.

"It was really very difficult – a rollercoaster. I was coming back from the AFCON and I was on a cloud. I started to play, have some good matches, [but] the one against PSG and that error came quickly.

"[Then] no news. No sign of life. The first week was horrible regarding the criticism. And Rosenior, who brought me, was quickly ejected."

He also explained how frustrating it was to remain on the sidelines without receiving an explanation.

"No longer doing your job, staying on the bench and watching your teammates play was very hard to experience, especially without any explanation."

However, his move to Real Sociedad has provided a fresh opportunity. Sarr has featured in all three of the Spanish club's Europa League matches and made six domestic starts, accumulating 733 minutes across both competitions.

The defender is enjoying a more productive spell in Spain, with Real Sociedad currently fifth in La Liga.

His departure could also become a concern for Chelsea manager Xabi Alonso, particularly following Maxence Lacroix's hamstring injury, which is expected to keep the defender out until the new year.