Tottenham midfielder Steven Pienaar has been ruled out for up to six weeks after undergoing groin surgery.

South Africa captain Pienaar was forced to go under the knife after injuring himself in Spurs' final pre-season friendly against Athletic Bilbao on Saturday.

The north London club said in a statement on their official website: "Following scans and consultation with an independent groin specialist, Steven Pienaar underwent groin surgery this morning.

"The South Africa international was forced off with the injury in the first half of Saturday's pre-season friendly against Athletic Bilbao and is expected to be sidelined with the injury for up to six weeks."

That would rule Pienaar, 29, out of up to eight games for Spurs, starting with Saturday's Premier League opener against Everton.

He would also sit out crunch meetings with Manchester United, Manchester City and Liverpool, as well as this month's Europa League play-off tie against Hearts and Tottenham's opening group match should they qualify.

Spurs is well stocked in midfield and should be able to cope with the absence of a player who has faced a battle to dislodge Gareth Bale on the left wing ever since his January move from Everton.

Tottenham is also on the lookout for reinforcements in the middle of the park, although they appear set to fail in their latest bid to sign Real Madrid's Lassana Diarra.

Spurs reportedly held talks with Real with the aim of landing the 26-year-old, but his wage demands look likely to scupper any deal.

Manager Harry Redknapp signed Diarra for Portsmouth in January 2008 and has made previous efforts to bring him to White Hart Lane.

Redknapp has also long been pursuing West Ham's Scott Parker but wages could also prove a problem in the Footballer of the Year's case.

Tottenham is reportedly willing to listen to offers for Jermaine Jenas and Wilson Palacios to make space for a new midfielder but are refusing to countenance any bids for playmaker Luka Modric.