The BVB forward is adamant that his side are fully prepared for their Champions League quarter-final with the La Liga gaints after dispatching Stuttgart on Saturday
Die Schwarzgelben warmed up for their trip to Spain with a 3-2 win over relegation-threatened Stuttgart, fighting back with a Reus hat-trick after being two goals down following early Christian Gentner and Martin Harnik strikes for the hosts.
The Germany attacker believes that his performance on Saturday shows that he is coming back into form after injury problems earlier in March and declared that his side will face Madrid with confidence.
"Goals are always good for self-confidence and we are ready for Real," the 24-year-old told Bild after the game.
"I've also been injured several times. For me it's not just about goals - it's more important that I find my rhythm and it keeps improving."
BVB reasserted themselves in second place in the Bundesliga after victory over Stuttgart, with Huub Stevens's men facing a very real danger of relegation as they sit 17th in the table following the result.
Jurgen Klopp's side now turn their attention to Los Blancos in the Champions League quarter-finals, a repeat of last season's semi-final, which saw the Germans resist a fightback to take a 4-3 aggregate win and proceed to the final at Wembley.
Dortmund travel to face Madrid on Wednesday with the return leg at the Signal Iduna Park on April 8.