Lewis Holtby wants to complete his move to Tottenham this month and has already undergone a medical at the club.

Spurs remain confident of agreeing a deal to bring forward the midfielder’s summer move from Schalke by six months, even though the clubs remain some way apart on the valuation.

Holtby is believed to have passed a medical earlier in January, an appointment that was planned before Sandro sustained a serious knee injury in the 0-0 draw with Queens Park Rangers.

He had originally agreed to move to White Hart Lane at the beginning of July, when his contract at Schalke will have expired, but Tottenham head coach Andre Villas-Boas is pushing hard to have Holtby now as he seeks greater depth in midfield.

Yet while Holtby, 22, will not rock the boat with his current club, Standard Sport understands the Germany international would favour a switch to north London now, rather than waiting until the end of the campaign.

Holtby is thought to be growing frustrated by the current impasse and uncertainty about his future. Spurs have offered a little less than £1million for the player, who would have qualified to play for England via his father, while Schalke are holding out for about £1.6m.

Spurs had hoped to have Holtby in time for Sunday’s FA Cup fourth-round tie at Leeds and could still wrap up a deal before the trip to Elland Road. Schalke’s next fixture in the Bundesliga is at Augsburg on Saturday.

Holtby had a superb game in his club’s 5-4 win over Hannover last weekend as German football resumed after its winter break and looked revitalised after his form had dropped in the final weeks of 2012.

Should Holtby remain in Germany, he would be able to continue with his club’s Champions League campaign, where they play Galatasaray in the last 16, but his preference is an immediate transfer to the Premier League.

Villas-Boas wants his chairman Daniel Levy to add at least two players before the transfer window closes and had planned to watch Celtic’s win over Dundee United at Parkhead last night, where forward Gary Hooper and midfielder Victor Wanyama were the main attractions.

But Spurs’s latest financial results may urge greater caution. The club announced a loss of £4.3m for last season, with revenue falling by 12 per cent from the 2010-11 campaign, mainly because the team did not compete in the Champions League last term.