Dimitar Berbatov's Fulham future is uncertain and he stands to make a deadline day move if the club were to sign the centre-forward they are chasing. René Meulensteen, the manager, has made Kostas Mitroglou of Olympiakos his top target while he has Ajax's Kolbeinn Sigthorsson as his back-up plan.

Berbatov, whose contract expires in June, has attracted the interest of Tottenham Hotspur and Arsenal, among other clubs, and his situation is delicate as Friday night's transfer deadline approaches.

The 32-year-old has moped in recent weeks after his agent, Emil Dantchev, went public at the beginning of last month over the striker's desire to get a January move from Craven Cottage. Fulham are of the opinion that Berbatov can leave but only if they were able to sign a suitable replacement.

The club's owner, Shahid Khan, fearful of the prospect of relegation from the Premier League, is prepared to release £15m-£20m for Meulensteen to spend on reinforcing the squad.

Fulham have made two unsuccessful offers for Mitroglou, the Greece international, of €10m and €12m, with Olympiakos holding out for €15m. Fulham hope to reach a compromise at around €13m.

Mitroglou, 25, was available last year for just £4m but his value has increased on the back of his prolific form this season. He has 14 goals in 12 league appearances plus three in five Champions League ties – all three of them coming in the 3-0 group stage win at Anderlecht. Olympiakos face Manchester United in the last 16.

Sigthorsson, the 23-year-old Iceland international, is less prolific and he has scored only seven league goals so far this season for Ajax. But Meulensteen rates him and he believes that he could represent value at €10m.

Berbatov enjoyed two seasons at Tottenham from 2006 before he left under acrimonious circumstances for Manchester United. It would be a sensation were he to return to White Hart Lane but Tottenham do need another striker, with Jermain Defoe set to join Toronto FC at the end of February. The manager Tim Sherwood has Emmanuel Adebayor and Roberto Soldado but he favours playing with two up front.

There was interest in Berbatov from Arsenal at the end of last month and Fulham mooted the idea of taking Nicklas Bendtner in a part-exchange deal, featuring a cash adjustment. Bendtner is also out of contract in the summer. But the Dane was injured on New Year's Day as he scored a crucial goal for Arsenal against Cardiff City and he has only just returned to fitness.

Berbatov is famously self-assured and one possible complication over a move for him would be his desire for guaranteed playing minutes.

Fulham, who have cooled their interest in West Ham United's Ravel Morrison, have signed the 28-year-old Denmark midfielder William Kvist from Stuttgart on loan for the rest of the season. They have the option to make the deal permanent in the summer. Meulensteen also wants the Tottenham attacking midfielder Lewis Holtby.