The long-awaited Friends reunion show will be missing one familiar face after Matthew Perry said he won't be there because he is too busy working a stage play in London.

Perry, who played the sitcom's Chandler Bing, said his schedule means he is unable to join his former cast mates for the one-off special on NBC, but he will introduce them in a video sent from the UK.

"I'm doing the play here so I can't be there," he announced in an interview on The Graham Norton Show.

The actor also warned that the show is "not the reunion everyone is hoping for" after reports the team were getting back together prompted feverish speculation of a new episode.

In fact, the two-hour special will be a tribute to director James Burrows.

Friends is one of the most iconic sitcoms of the 1990s, making worldwide celebrities of its star members as it ran between 1994 and 2004.

Fans have long hoped for a reunion, though efforts to bring all six cast members back together on television have proved difficult.

NBC entertainment chairman Robert Greenblatt suggested earlier this week that the new reunion may not feature the six actors together, saying he was not sure if they could pull it off "logistically".

Whilst the other six stars will be taking part, Perry will be busy with his play The End Of Longing, which he both wrote and stars in.