BERLIN — When Wladimir Klitschko steps into the ring against Ruslan Chagaev at Veltins Arena in Gelsenkirchen on Saturday, it will be in front of the largest boxing audience in Germany since Max Schmeling fought in the 1930s.

Action inside the ropes, however, might not live up to the hype.

Klitschko, the IBF and WBO heavyweight champion, was supposed to be fighting David Haye to settle a running verbal feud. But Haye bowed out earlier this month, saying he had injured his back.

Haye asked to reschedule the fight in July, but Klitschko wanted to keep the date and the 60,000-seat sellout — the biggest boxing crowd in Germany since Schmeling fought Adolf Heuser in front of 70,000 people in Stuttgart on June 2, 1939.

"It's a chance that's coming around for the first time in my entire sporting career," the 33-year-old Ukrainian said. "I'm incredibly excited about the 60,000 fans."

The 30-year-old Chagaev was named the WBA's "champion in recess" in 2008 after withdrawing from two fights against Nikolai Valuev. After a third bout between the two scheduled for last month in Helsinki was canceled due to Hepatitis-B antigens being found in Chagaev's blood, the WBA announced Valuev as the rightful champion and put Chagaev's honorary title "under review."

As of Friday, the WBA had not clarified whether Klitschko (52-3) will fight for a piece of that title on top of defending his belts.

Michael Ehnert, the medical doctor for Universum, which is promoting Saturday's fight, said Chagaev is fit to fight in Germany.

"Since getting Hepatitis B many years ago, Ruslan is simply a carrier of Hepatitis-B antigens. This has not led to an infection," Ehnert said.

Klitschko has said he has been immunized against Hepatitis B and is not worried about the fight.

In February, Chagaev (25-0 with one draw) won a technical decision over Carl Davis Drumond in Rostock, Germany. It was the Uzbekistan-born boxer's first fight in more than a year.