"He was great," Winston told The Hollywood Reporter after concern arose following the airing of the special, in which Perry slurred his speech and appeared to be lethargic.
"People can sometimes just be unkind. I wish they weren’t," Winston added. "I loved working with him."
According to Winston, the 51-year-old is a "brilliantly funny man" with great one-liners on Friends: "I felt just happy and lucky to be in his presence and directing him on something like this."
It has since been reported that Perry is sober and his slurred speech was caused by dental work.
"Matthew turned up to the reunion and members of his team said that he had an emergency tooth procedure that day," an insider told The Sun. "That was said to impact his wellbeing and also how he was feeling."
"Obviously no one wants to film after a [dental] procedure, but it happened," the insider explained. "The feeling was one of huge sympathy for Matthew especially in recent days given how people have reacted online."
The insider concluded, "Matthew has told those around him that he is sober, and there is no need to worry."
Friends executive producer Kevin Bright also assured fans that Perry is fine. "It was great seeing him again. And what people say is what people say," Bright told THR. "I don’t have [anything] to say about that, except it was great to see him."
"And I think he’s very funny on the show. But yes, I think he’s OK," the 66-year-old added. "He seems stronger and better since the last time I saw him, and excited about going forward."
Perry struggled with addiction throughout his time on Friends after the actor was prescribed Vicodin following a jet ski accident in 1997. He was in and out of rehab for several years.
"I don’t remember three years of it," he once told BBC of his time as Chandler Bing on the comedy. "I was a little out of it at the time — somewhere between seasons three and six."