Federer feels nervous ahead of final pro match

LONDON, Sept. 21 (Xinhua) -- Swiss legend Roger Federer said here on Wednesday that he felt nervous as he was going to play his last match as a professional tennis player.

The 20-time Grand Slam winner announced last Thursday that he would retire from Grand Slams and the ATP Tour after the Laver Cup held from September 23 to 25 in London.

According to the Laver Cup format, each player competes in at least