The heat is on for Group F rivals BVB and Napoli

Six months ago, Borussia Dortmund were winning the hearts of football fans across Europe with some thrilling football en route to a UEFA Champions League final appearance against FC Bayern München.

On Tuesday night, in the words of their Greek defender Sokratis Papastathopoulos, they face a decider of a different kind as they host SSC Napoli in a Group F match that they must win to retain any hope of reaching this season's round of 16. "It will be like a final for us tomorrow," said Papastathopoulos and, unlike in May, Jürgen Klopp's men will enter it on a downer.

Klopp's injury-hit team have lost twice in the Bundesliga since their matchday four defeat by Arsenal FC, 2-1 at VfL Wolfsburg and then 3-0 at home to Bayern on Saturday. They sit third in Group F, three points behind Napoli and in Papastathopoulos's words "are missing two very important centre-backs" in Mats Hummels and Neven Subotić". Yet he kept an optimistic outlook as he surveyed the challenge Tuesday night will bring.

"I think we played well in defence against Bayern München at the weekend," said Papastathopoulos, who partnered emergency signing Manuel Friedrich at the back. "Then we conceded the first goal and had to open up a bit, which allowed them two more goals.

"I think all the players know what is at stake," he added. "We have had many talks since Saturday and are totally programmed on a win. We know we still have matters in our own hands and will not see that chance taken away from us."

Defiant words, but Dortmund may not find it easy against a Napoli side desperate to make amends for their own recent disappointments, according to goalkeeper Pepe Reina. Rafael Benítez's team have lost two in a row in Serie A, following up a 3-0 defeat at Juventus before the international break with the weekend home loss to Parma FC and Reina said: "We go into tomorrow's game with even more determination to win after the two recent defeats.

"While you are maybe allowed to lose at Juventus, the home defeat against Parma was more of a shock to us. But we must remember that we have a very new team here and we are still creating this new team, so setbacks are inevitable. We still came here, formed a totally new team and managed the best start in the club's history in Serie A."

Reina knows the UEFA Champions League well, having played in the 2007 final with Liverpool FC, and stressed that Napoli must go into Tuesday's match with a positive mind-set, and not simply play for the draw that would secure qualification. "We know a draw would see us through, but we should not play for one. That could be very dangerous. We have to try to play our own game and not focus too much on what Dortmund are going to do."