Jermain Defoe's return to White Hart Lane has put the future of Tottenham's other forwards in serious doubt, although Roman Pavlyuchenko can tonight stake a claim to become the England striker's regular partner.

Defoe arrived at Spurs this morning after a fee of almost £16million was agreed with Portsmouth and should make his second "debut" for the north London club in Sunday's Premier League fixture at Wigan.

But while fans will celebrate Defoe's signing, it spells trouble for the first-team prospects of Pavlyuchenko, Darren Bent and on-loan Manchester United striker Frazier Campbell, who have collectively failed to fill the void created by the summer departures of Dimitar Berbatov and Robbie Keane.

Defoe prospered at Portsmouth by playing alongside Peter Crouch, which suggests that Pavlyuchenko, who has scored nine goals since joining from Spartak Moscow in the summer, is his most likely ally up front. Of Spurs' existing strikers, Pavlyuchenko's style is most similar to Crouch's, with both able to link the play in attack.

For Bent, the future is more worrying. Like Defoe, he is more of a penalty box player and although he scored seven times in Harry Redknapp's first five matches at Spurs he has netted just once since 9 November. Furthermore, Bent is sidelined with a groin injury so Pavlyuchenko and Campbell will start tonight's first leg of the Carling Cup semi-final against Burnley.

Campbell is on a year's loan from Manchester United, but continues to attract interest from Hull, whom he helped to promotion last season.

Defoe's valuation has risen by £7m since he was sold by Spurs last January, but the player has built on his impressive goalscoring record at Fratton Park.

During his first spell at Tottenham, from January 2004 until January 2008, he scored 43 goals in 139 Premier League appearances, and followed it up with 15 in 31 League games for Pompey. Spurs' principal weakness in recent weeks has been a lack of killer instinct in front of goal. They have scored just once in four League games, and Redknapp is banking on the 26-year-old's penalty-box acumen to make his team more dangerous.

Today, the attention at White Hart Lane has been directed towards Defoe but tonight, the club's focus will turn to the Carling Cup where they will face a Burnley team who have already knocked out three London clubs this season.

Fulham, Chelsea and Arsenal have all been despatched by Owen Coyle's impressive Championship side on their remarkable run to the last four. All three clubs are above holders Tottenham in the Premier League table and Burnley will feel confident about their chances over two legs.

They beat Chelsea at Stamford Bridge on penalties after a 1-1 draw in the fourth round in November. And this came sandwiched between a 1-0 win over Fulham at Turf Moor, and a 2-0 home defeat of Arsenal in the quarter-finals.

Such is Burnley's strength at home - they have lost only two of 13 games there in the Championship this season - that Spurs will need a convincing victory at White Hart Lane tonight if their minds are to be at rest when they travel to Lancashire for the second leg in a fortnight.

Redknapp knows all about the difficulties of facing Championship opponents. His Portsmouth side beat five clubs from the second tier - including Cardiff in the final - on their way to lifting the FA Cup last season, winning all of those matches by only one goal.

The Spurs boss said: "I saw Burnley on Saturday (in their 0-0 draw at Queens Park Rangers in the FA Cup). They have done well this season. They are well-organised, with some experienced players, and they have been on a fantastic run.

"Owen Coyle has done a great job, and with them beating Fulham, Chelsea and Arsenal already, they cannot be underestimated. We are so close to the final, and it is a fantastic chance for us to get their for the second year running, and to try to retain the trophy.

"Staying in the Premier League is the priority, but the Carling Cup is very important to us.

"Winning it for its own sake is more important than getting into Europe again, as it was when we won the FA Cup with Portsmouth."

With his side enjoying a return to form in the 3-1 FA Cup win over Wigan last Friday, Redknapp will be pleased that Burnley have little desire simply to look for a 0-0 draw.

Spurs have struggled this season when confronted with defensive opponents, but Clarets manager Coyle insisted: "We will not go to White Hart Lane and be negative. We have caused a few upsets this season, so let's hope for another."