The 25-year-old Ukrainian was cleared to return to football last Friday by the FA and the World Anti-Doping Agency, after serving a lengthy suspension for testing positive for the banned substance meldonium.
Mudryk had originally been hit with a four-year ban, but the sanction was lifted following changes to WADA's technical guidance on permitted concentration levels, with the governing body confirming that his case would not have resulted in a violation under the current rules.
According to teammate Tosin Adarabioyo, Mudryk worked relentlessly to stay in peak condition throughout his time out of the game.
"Misha is a freak. His work ethic is incredible. There is no doubt he has worked hard the whole time," Adarabioyo told the BBC.
The defender also revealed he had stayed in regular contact with the winger during the suspension.
"Misha is my guy. I've stayed in touch with him the whole time, and it's really nice to have him back. I'm really happy for him."
Mudryk made his long-awaited comeback on Wednesday, coming off the bench in Chelsea's 1-0 pre-season defeat to Juventus at the Kai Tak Stadium in Hong Kong, having last featured for the club in November 2024.
The winger, who joined Chelsea from Shakhtar Donetsk in January 2023, remains under contract at Stamford Bridge until 2031, though his immediate future at the club is uncertain, with reports suggesting a loan move could still be on the cards as he looks to rebuild his career under Xabi Alonso.