Rafael Nadal's Grand Slam count will stay stuck at 11 for now, sidetracked by another knee problem.

The third-ranked Spaniard withdrew from the U.S. Open on Wednesday. Tendinitis has kept him out of action since his stunning loss at Wimbledon in late June.

England pulled off their first victory over Italy in 15 years in a friendly on Wednesday, while world champion Spain eased past Puerto Rico 2-1.

Visiting South American giants Argentina and Brazil also notched up comfortable victories over Germany and Sweden.

Novak Djokovic, Andy Murray and Roger Federer won their opening matches at the Western and Southern Open near Cincinnati in straight sets Wednesday, getting accustomed to the heat after spending the last two weeks in London and Canada.

Djokovic got the bronze medal at the Olympics in London, then won the Rogers Cup in Toronto on Sunday night. He was a little off in his opening set on a court baked in sunshine and 86-degree heat, before pulling away from Andreas Seppi of Italy 7-6 (4), 6-2.

After Manchester City secured its first Premier League title in a dramatic finale last season, it was widely believed manager Robert Mancini would again spend big to usher in an era of domination in English football.

But the lack of action speaks volumes - City has only signed midfielder Jack Rodwell from Everton during the summer.

Bolton midfielder Fabrice Muamba retired from football Wednesday after suffering an on-field cardiac arrest in March during an FA Cup quarterfinal against Tottenham at White Hart Lane.

Muamba travelled to Belgium last week to seek further medical advice from a cardiologist after consultations in Britain and Europe, and has been advised to retire from playing at the professional level.

ATP Cincinnati Masters second seed Novak Djokovic says he has to remind himself which continent he is on as his fast-paced schedule spins swiftly with the Olympics done and the U.S. Open near.

"If you don't keep track of time and places where you are, it happens -- sometimes you wake up and say, 'OK, which time zone am I in right now?,'" Djokovic said.

After deposing Barcelona and sending its coach Pep Guardiola into early retirement, Jose Mourinho's Real Madrid now faces the challenge of defending its Spanish league crown while seeking that elusive 10th European Cup.

Mourinho was give two objectives when he joined Madrid: break Barcelona's domestic hegemony and return Madrid to the heights of European football with a first Champions League trophy since 2001.

Manchester City captain Vincent Kompany has no doubt the arrival of want-away Arsenal striker Robin van Persie would make the English Premier League champions a stronger side.

With just days to go until the start of the new season, Arsenal's reported £20 million asking price for the striker, who scored a mammoth 37 goals last term, has yet to be met.

A judoka and three coaches from the Democratic Republic of Congo's Olympic delegation, listed as having gone missing after leaving the Athletes' Village at the London Games, missed their flight home - but the judoka says he is on holiday, an official source said Tuesday.

Cedric Mandembo, who competed in the +100kg category, boxing coach Blaise Bekwa, athletics coach Guy Nkita and judo coach Ibula Masengo have not been seen since the Games came to a close on Sunday evening, a sports ministry source had said Monday.

French international footballers Franck Ribery and Karim Benzema are to face trial for allegedly soliciting an underage prostitute, judicial sources said on Tuesday.

The footballers are among eight people that investigating magistrate Andre Dando has sent for trial as well as the Zaman Cafe on Paris' Champs Elysees where the meetings with Zahia Dehar took place.