Norwich defender Christoph Zimmermann is a doubt for the start of the new Premier League season after undergoing knee surgery.
Zimmermann sustained a medial meniscus tear in his left knee during the summer and underwent surgery on the injury in London last week.
The 26-year-old is expected to miss the next four to six weeks, making him a major doubt for the club's opening game of the season against Liverpool on August 9.
The Canaries travel to face the European champions at Anfield, live on Sky Sports, in their first game back in the Premier League.
Zimmermann will continue his rehabilitation at the club's Colney Training Centre after signing a new four-year deal with Norwich on Tuesday.
"I am very thankful to the club for offering me the opportunity to extend my contract and to sign a new deal," he told the club's official website.
"I think from when I started, I never made a secret of what the people, club and the whole region means to me and how my feelings are for everything we are doing here so for that of course, I am really pleased and happy to have four more years with Norwich City.
"There is lots of excitement about the new season and we are really happy to be in the Premier League.
"But also we need to take responsibility and enjoy the games to get the right results and enough points to reach our goals."