Semifinal 2, 2nd leg: TodayReal Madrid     vs     Dortmund    20:00 SS3MADRID: Real Madrid are sweating on the fitness of Cristiano Ronaldo as they go in search of an unlikely comeback in the second leg of their Uefa Champions League semifinal against Borussia Dortmund on Tuesday.The Germans are huge favourites to progress to the final at Wembley on 25 May after four goals from Robert Lewandowski handed them a 4-1 win over the Spanish champions in the first leg at Signal Iduna Park last week.And any hope of a Madrid revival would seem to depend on their talisman overcoming a thigh strain he suffered in the first leg.The Portuguese has scored 50 per cent of Real’s 24 goals in the competition so far this season, but missed Saturday’s 2-1 win over Atletico in the Madrid derby and also took part in a solitary training session with physical trainer Carlos Lalin on Sunday.However, midfielder Angel di Maria believes Jose Mourinho’s men can take heart from the way in which they started last season’s semifinal, second-leg against Bayern Munich.Trailing 2-1 from the first leg, Real stormed into an early 2-0 lead on the night and although they ended up going out on penalties, Di Maria said they have to start with the same intensity on Wednesday."We have a great chance of going through,” he told reporters after scoring the winner against Atletico on Saturday night."Last year, against Bayern, we started well and were 2-0 up. We hope that this year we can turn it around, but we need to give everything. In football anything can happen.Presuming Ronaldo is fit, Di Maria’s inclusion in the starting line-up is likely to be the only change in the Real side from the first leg.Dortmund, meanwhile, have injury concerns of their own with Polish international full-back Lukasz Piszczek struggling with a groin injury he picked up in the first leg.Midfielders Ilkay Gundogan (neck) and Mario Gotze (hip) are also carrying knocks and manager Jurgen Klopp made 10 changes for Saturday’s 2-1 win at Fortuna Dusseldorf.