"I went to Germany earlier this week to get it looked at," he said. "I've been having a pain in my Achilles for some time but I didn't want to miss any games. When you're in the team and playing well you don't want to miss any matches.
"It was hurting whenever I made a movement. The plan was always for me to get it checked out properly after the Arsenal game but it became too painful during the match and I couldn't continue.
"I had an x-ray after the game, but it didn't show serious damage, so I decided to go to Germany.
"I visited Muller-Wolfhart while I was at Slavia Prague and also during my time in France. He has a very good reputation and has helped a lot of top players.
"The Czech Republic have already qualified so there is nothing at stake in their match with Austria. It gave me the chance to sort it out."