When Adebayor arrived at White Hart Lane on loan from Manchester City last summer, there were serious doubts about his temperament, but he has defied the critics to become a key player for Spurs.

The Togo striker has scored 14 goals and his physical presence up front has allowed the likes of Rafael van der Vaart, Gareth Bale and Luka Modric to prosper in midfield.

The 28-year-old wants to stay at Tottenham, but his reported wage packet of £170,000 a week will prove to be a big stumbling block in any negotiations.

Redknapp would love to keep the former Arsenal striker, but is unsure whether a deal can be agreed.

The Tottenham manager said: "He scored two goals last week against Swansea and he has been excellent, but whether it's possible to do a deal, I wouldn't be sure.

"Manu is on loan at the moment and that's where we're at.

"The chairman will deal with (any negotiations) at the end of this season. I wouldn't have a clue whether (a permanent transfer) is a possibility or not."

Critics have claimed that City, who now trail Barclays Premier League leaders Manchester United by five points, made a mistake in letting Adebayor go, despite his previous troubles with Blues boss Roberto Mancini.

Reports claim some of City's players want Adebayor back at the Etihad Stadium next season, but Redknapp doubts that will happen.

"His future doesn't seem to be there," Redknapp added. "He probably needs to move on.

"City have just gone through a dicky little spell recently but they have lots of good strikers there.

"If you look at the quality they have up front, they are full of top players."

Adebayor's brace against Swansea last Sunday brought Tottenham their first win in six league matches.

The victory, and Arsenal's defeat at QPR last Saturday, means Spurs have a chance to move three points clear of their north London rivals tomorrow if they win at Sunderland.

Redknapp feels his team are now back to their best but has warned any slip-ups in their run-in could prove costly as Chelsea and Newcastle trail his team by just five points with seven games left.

"Last week we had a good week, beating Bolton in the FA Cup and beating Swansea and drawing at Chelsea in the league, so we are in good form again," he said.

"We can't afford to drop too many points, though, because Arsenal, Chelsea and Newcastle are all right there.

"It will be a right dog fight until the end so we have to go up there and make sure we get the right result."

Tottenham's poor away form is one of the main reasons why they dropped out of the title race at the turn of the year.

Redknapp's men are without an away league win in 2012, their last victory on the road coming at Norwich on December 27.

Tomorrow's game will not be an easy fixture given that Sunderland have impressed lately under Martin O'Neill, who has dragged the Wearside club from the relegation zone to ninth since taking over in December.

"Martin has come in, and as Martin always does he has got them up and going straight away and has done a great job there," Redknapp said. "They are a difficult team to play against.

"He is full of enthusiasm still and it's good to see him back in management again. He is a great character and a top manager.

"They had a great result drawing at Manchester City last weekend and it will be a difficult game but we have to keep going."