The 25-year-old did not train with his teammates Sunday morning before the 23 Real players boarded their flight for the camp in Irdning in the Austrian mountains.

Cassano joined Real Madrid from AS Roma in January 2006 for five million euros (6.9 million US dollars) but has been unable to command a regular first-team place.

He was briefly suspended in October 2006 following a bust-up with then Real coach Fabio Capello and has had trouble keeping his weight down.

Real captain Raul said he did not know the reason for Cassano's absence.

"You'll have to ask the director of sport for more details. Cassano hasn't been at training, we players know little more than this," he said.

Brazil's Julio Baptista, Marcelo and Robinho and Argentina's Gago were also left out of the training camp as they are recovering after competing in the Copa America with their national sides, the club said.

Friendlies are planned in Hanover, Germany and Moscow with the team returning home on August 5.