Borussia Dortmund will not wait for midfielder Manchester United target Ilkay Gundogan until the summer to decide on a contract extension. Gundogan has missed almost all of the season with a back injury, however, the midfielder remains a key player for Jurgen Klopp’s side, who sit second in the Bundesliga, and his performances have attracted the interest of a host of clubs. Along with Man United, the likes of Barcelona and Real Madrid have also been linked with bids for the 23-year-old, whose contract at Dortmund is set to expire at the end of next season. The German club have offered Gundogan an extension, but are still awaiting a response from the midfielder and CEO Hans-Joachim Watzke has issued a warning that Dortmund will not wait until the summer for a decision to be made. Ilkay is a major player in our squad and we want to keep him for the club, Watzke told Bild. We have made him a contract proposal. We are not going to wait until the summer for an answer.” Gundogan has made just three appearances in all competitions for Dortmund this season, all of which came in August, but could be set to return to the side next month. Watch Barcelona v Atletico Madrid in the Champions League on Tuesday. 24 hour Sky Sports day pass for only 9.99. No contract. Read more Manchester United transfer news.