SAO PAULO, Brazil - Two-time gymnastics world champion Diego Hypolito will undergo knee surgery on Tuesday.

Diego Hypolito of Brazil performs on the floor during the all-around team competition at the 40th World Artistic Gymnastics Championships in Stuttgart in this September 3, 2007 file photo. [Agencies]

The procedure, a right-knee arthroscopy, is likely to sideline Hypolito for about four weeks, coach Renato Araujo told local media.

"We don't know exactly when the injury happened," Araujo said. "He began feeling the pain last Friday and medical exams showed the surgery was necessary."

Araujo said the surgery will disrupt the Brazilian athlete's preparations for the Beijing Olympics in August.

"Obviously it will be a problem," he said. "He will have to miss training sessions, and practice time is always important. He will have to overcome this."

Hypolito won the 2007 world championship in the floor exercise and is among the favorites for the gold in Beijing.

He also won the event in 2005 and was runner-up in 2006 despite losing training time because of an ankle injury.