The 2022 Laver Cup's first doubles match could be the final match of Roger Federer's professional career.

The 20-time Grand Slam winner, who announced his upcoming retirement from professional tennis last week, explained his knee condition would limit his participation in the fifth edition of the tournament.

He also hinted the Friday doubles match might be his only match at the O2 Arena.

"I am quite surprised how well I am playing in practice here. But it was already clear beforehand that I would only play doubles, probably on Friday evening. That's why playing the Swiss Indoors in Basel was no longer an option," the 41-year-old told the Swiss media on Tuesday.

"It was tough, the whole comeback was extremely difficult. I was so far from 100 percent. Reaching the quarter-finals at Wimbledon was unbelievable for me. The last set against [Hurbert] Hurkacz was one of the worst hours of my career."

At the time of writing, it is unknown which player from Team Europe, consisting of Rafael Nadal, Novak Djokovic, Andy Murray, Casper Ruud and Stefanos Tsitsipas, will partner him on Friday.

Federer added that he was at peace with his decision to hang up his racquet.

"A few days after Wimbledon, in July, the knee just wasn't progressing anymore. I asked myself: what's the point? We had been on thin ice for a long time.

"I know [my retirement] is the right decision, the only good decision."