Rafael Nadal, who pulled out of the U.S. Open due to injury, should be ready for the Davis Cup semifinal between Spain and the United States next month, the tennis ace's coach and uncle said Thursday.

The Spaniard withdrew on Wednesday from the U.S. Open, the final Grand Slam of the season, which starts in New York on August 27, because of his continuing battle with knee tendinitis.

Liverpool agreed a deal to sign Morocco winger Oussama Assaidi from Dutch club Heerenveen for an undisclosed fee on Thursday.

Assaidi has to pass a medical before the transfer can be rubber-stamped, but if it is completed successfully he will become new boss Brendan Rodgers' third signing since he took over from Kenny Dalglish in June.

Arsenal coach Arsene Wenger said he would have preferred to sell star striker Robin Van Persie to Paris St. Germain rather than Premier League rivals Manchester United.

Van Persie is expected to complete his move to Old Trafford within the next 24 hours after Arsenal accepted a bid of around £22 million ($34 million) for their captain.

Tottenham manager Andre Villas-Boas said Luka Modric is training on his own while the midfielder holds discussions with Real Madrid about a move to the Spanish champions.

The Croatia international is widely reported to be on the verge of joining Madrid in the coming days, ending his four-year spell at Tottenham.

Manchester United said Wednesday they had agreed a deal to sign Dutch striker Robin Van Persie from Premier League rivals Arsenal.

"Manchester United is pleased to announce it has reached agreement with Arsenal Football Club for the transfer of Robin Van Persie," said a club statement.

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.