Bundesliga strugglers have been dealt a blow with the news that Lewis Holtby is set for a 10-week spell on the sidelines after breaking his collarbone in a 3-2 friendly victory over Eintracht Frankfurt on Thursday.
The midfielder was introduced as a second-half substitute and fell awkwardly during a challenge with Martin Lanig.
Holtby was subsequently taken for scans and the former Tottenham man is set to remain in hospital to undergo surgery on his injury.
"It's terribly disappointing for Lewis," Hamburg head coach Joe Zinnbauer told the club's official website.
"I feel really sorry for him. We'll support him as best we can."
The news is bad timing for a Hamburg side who entered the Bundesliga's mid-season break just two points above the bottom two and level with Werder Bremen, who occupy the relegation play-off position.
Hamburg resume their Bundesliga campaign at home to Cologne on January 31.