Heavyweight champion Vitali Klitschko suffered a torn ligament in his left shoulder during his unanimous decision win over Dereck Chisora on Saturday in Munich, Germany, but he will not require surgery.
"Vitali suffered a small rupture of a ligament in his left shoulder, which is why he was not able to use his left hand as he wanted to use it," Klitschko spokesman Klaus Dittrich told ESPN.com on Sunday.
The injury occurred in the third round, Dittrich said.
During his in-ring, post-fight interviews, Klitschko declined to confirm the injury, although he did say later that he had hurt his shoulder during the fight.
Dittrich said Klitschko was examined at a Munich hospital after the fight but it "showed that surgery seems not to be needed."
Instead Klitschko will use physical therapy to rehabilitate the shoulder. However, it does throw his planned schedule off course. Klitschko had planned to fight three times this year with a June fight followed by another fight in the fall.
"The plan for Vitali's next fight is in September," Dittrich said. "Until then he needs to rest and (have) physical therapy. Regardless of the injury, this will definitely not be his last fight. He is up for more."
It was evident early on that Klitschko, 40, had become a one-handed fighter against Chisora, relying almost exclusively on his right hand. Typically, Klitschko's best weapon is his left jab, which disappeared after the first few rounds.
For the fight, Klitschko averaged just 22 jabs thrown and five landed per round, according to Epix punch statistics. In his previous eight fights, Klitschko averaged 44 jabs thrown per round and 12 landed, according to Epix.
Klitschko (44-2, 40 KOs), who is from Ukraine but fights mainly in Germany, defeated England's Chisora (15-3, 9 KOs) on scores of 119-111, 118-110 and 118-110 to retain his title for the eighth time in his third title reign.
The left shoulder injury is not the first Klitschko has suffered.
In 2000, Klitschko tore the rotator cuff in his left shoulder against Chris Byrd. The injury caused Klitschko to retire on his stool after the ninth round of a fight he was winning in lopsided fashion and yield his version of the heavyweight title.
Dan Rafael is the boxing writer for ESPN.com. Follow him on Twitter.