Barcelona striker Lionel Messi has suffered an injury during training and will not travel to play Hamburg for the German club's 125th anniversary celebrations, the Spanish giants announced on Tuesday.
"During training yesterday (Monday), the player suffered bruising to his right calf," the club said on its website.
"This morning (Tuesday), he underwent an ultrasound that showed he has intramuscular haematoma."
Messi had been due to be one of the main attractions for Tuesday's game in the continued absence of Spain forward David Villa, still recovering from a broken leg that forced him to miss La Roja's successful defence of their European title.
Barca said last week that he was "close to full form".
The game at the Imtech Arena will be Tito Vilanova's first in charge after taking over from Pep Guardiola.
Barca are due to play five friendlies before the start of the season.