Vitali Klitschko may return in a summer showdown with seven-foot former WBA world champion Nikolai Valuev. According to BILD, the proposed bout would take place in the 61,000-seat Schalke Arena in Gelsenkirchen, Germany, where brother and IBF/WBO/IBO heavtweight champion Wladimir Klitschko defeated Ruslan Chagaev last year. The current stumbling block is Valuev co-promoter Don King, who is holding out for a $4 million purse, a figure Klitschko’s manager Bernd Bönte told BILD was “Impossible even if Valuev had four belts and was undefeated.” He added that if Valuev doesn’t come aboard, there are other alternatives. Kalle Sauerland of Sauerland Event, Valuev’s other co-promoter, is optimistic that Klitschko-Valuev can be made. “This is an absolute must-fight,” he said. “We’ll find a solution. I think we’ll get this fight sorted out.”