BERLIN: Bayer Leverkusen must prove they can keep winning without their injured striker Javier Hernandez when they meet Bundesliga powerhouse Borussia Dortmund on Sunday. The Mexico international has been a sensation since joining this season from Manchester United, grabbing 13 goals in the league and scoring a total of 22 times in 26 matches in all competitions so far. But a muscle injury in their German Cup quarter-final loss to Werder Bremen last week put the 27-year-old out of action just as Leverkusen were on a good run of form. They have gone six league games without defeat, having lost just once in their last nine Bundesliga matches. Hernandez, who has a contract to 2018, was missed in Leverkusen's 2-1 win over promoted Darmstadt 98 on Saturday. The team had to struggle back from a goal down with help from an own goal and a 77th minute winner. But his absence will be felt even more keenly against their second-placed visitors. Leverkusen, who trail Dortmund by 13 points, have won none of their last eight home games against the Ruhr valley club. Dortmund have their own goal-scoring machine in Pierre-Emerick Aubameyang, with the Gabon international having netted 20 times in the league and Dortmund enjoying the joint-best attack along with leaders Bayern Munich. 'We have shown that we can keep winning without Javier,' Leverkusen coach Roger Schmidt said. 'The team has improved in the past weeks. I don't even know if we should say it out loud that we are third in the Bundesliga.' The club has not given a firm timeframe for how long Hernandez will be absent, but Schmidt has said that he hopes it will only be a couple of weeks. With speculation of a possible return to England's Premier League at the end of the season despite his contract, Leverkusen are eager to finish in the top four to secure a Champions League spot for next season and keep Hernandez. The problem is they must do this without his goals, at least for now. 'If we qualify for the Champions League then we have very good chances that he will stay with us,' said club CEO Michael Schade. 'As things stand now we do not want to sell any player.' 'We are, however, a commercial enterprise and there are limits. If there are huge offers then we will look into them,' he said. Dortmund, with three wins out of four matches since the winter break have tightened their hold on second spot and are eight points behind leaders Bayern, who host Darmstadt on Saturday. Fourth-placed Hertha Berlin, on 35 points along with Leverkusen, take on VfL Wolfsburg