Sunderland captain John O'Shea will return home from the club's pre-season tour in Germany following an injury.
The 30-year-old defender tweaked a muscle on his first appearance for the club against Arminia Bielefeld on Sunday following a recent move from Manchester United.
Republic of Ireland international O'Shea will head back to England on Wednesday and miss friendly fixtures against Hannover 96 and Borussia Monchengladbach.
Black Cats manager Steve Bruce admits it is a blow but will not risk O'Shea's fitness ahead of the new season.
He told the club's official website: "There's no point in taking risks during pre-season.
"John isn't going to play against Hannover or Monchengladbach, so we thought it would be easier if he flew home early to rest up and he can come back stronger when we return from Germany."