The Ukraine winger tested positive for a low concentration of the banned substance meldonium and was provisionally suspended before the Football Association charged him with an anti-doping rule violation.
He was originally handed a four-year ban but appealed to the Court of Arbitration for Sport, and the case was ultimately resolved after changes to World Anti-Doping Agency technical guidance meant the concentration found in his sample would no longer constitute a violation under current rules.
Mudryk accepted he had committed the violation as part of the settlement, with his ban reduced to time already served.
Speaking to Chelsea's in-house media after returning to action earlier this month, Mudryk described the toll the process had taken.
"I feel good. I feel amazing. I'm grateful to be back on the pitch. It was such a lovely feeling seeing everyone again. It was a warm welcome I got," he said.
"I'd say it's felt like an 18-month pre-season. I've trained, and I've trained hard. I didn't give up, and I just tried to work as hard as possible.
"I grafted six days a week with proper recovery, with a proper sleep schedule, food, everything. Everything was the same, just two sessions a day.
"The goal was to come back and show myself off again in the football world. That was my mission, and I knew what I had to do to achieve it. Only through hard work can you achieve something."
Mudryk joined Chelsea from Shakhtar Donetsk for around £62m in January 2023, signing an eight-and-a-half-year contract, and had made 73 appearances and scored ten goals for the club before his suspension.
His return gives head coach Xabi Alonso an additional attacking option as Chelsea's season gets under way, though it remains to be seen how quickly he can rediscover match sharpness after such a lengthy absence.