Germany captain Michael Ballack has injured his right ankle while playing for Chelsea in the FA Cup final.
The midfielder will undergo tests Sunday to determine whether he will be fit for Germany's World Cup opener on June 13 against Australia.
"It's not that good at the moment, but I have to wait until tomorrow for the scan, and then we will know more," Ballack said. "I went off and couldn't carry on, but it's not that bad."
Ballack went down clutching his ankle after a challenge from Portsmouth's Kevin-Prince Boateng. Ballack hobbled off in the 44th minute.
"It's not good in football when that happens, and nobody wants to see it," Ballack said. "He got away with a yellow and was lucky."
Chelsea went on to beat Portsmouth 1-0 when Didier Drogba scored his 37th goal of the season, curling in a free kick off a post in the 59th minute.
"We don't think it is a bad injury," Chelsea manager Carlo Ancelotti said. "We hope he will be ready for the World Cup."
