LONDON, July 2 - Germany captain Michael Ballack will undergo more surgery on his problem ankle on Tuesday, his club Chelsea said on Monday.

The 30-year-old midfielder missed Chelsea's victory over Manchester United in the FA Cup final and two German Euro 2008 qualifiers in June, following a major operation on the ankle at the beginning of May.

Chelsea said on their Web site (www.chelseafc.com) that the operation would take place in Germany, adding: "The operation is related only to a complication in the healing of the wound from previous surgery in May."

Ballack injured the ankle against Newcastle United in a Premier League match on April 22.