There are fears Alessandro Nesta could be out for a month after dislocating his shoulder.
The Milan defender fell awkwardly on to his left shoulder and arm during the first half of tonight's 2-0 win over Cesena.
He was taken to hospital for x-rays and the initial reports are of a dislocation, but not the feared fracture or ligament damage.
It would be a particularly heavy blow for the veteran, as he suffered an identical injury to this shoulder in 2007 and was forced to stay on the sidelines for three months.
The shoulder has been put back in place under anaesthetic, so no surgery appears to be required, but it is still an injury that should keep Nesta out for at least three weeks.
This was not a fortunate evening for the Rossoneri, who also lost Gennaro Gattuso in the warm-up due to a muscular problem.
With Andrea Pirlo, Clarence Seedorf, Mathieu Flamini, Kevin-Prince Boateng and Gianluca Zambrotta already sidelined, it forced Thiago Silva to fill the gap in midfield.