Germany defender Antonio Ruediger has been ruled out of the European Championship after suffering a knee injury in training on Tuesday.

Ruediger tore a cruciate ligament in his right knee, the German football federation said. A decision was yet to be made on a replacement.

The 23-year-old Ruediger is likely to miss around six months after sustaining the injury in a tussle with Thomas Mueller.

The loss of the Roma defender is a blow for Germany coach Joachim Loew, who had been counting on him to replace Mats Hummels, currently sidelined with a calf injury and unlikely to feature in any of the group games.

Ruediger, who had started Germany's last five internationals, joins Borussia Dortmund players Ilkay Gundogan (knee) and Marco Reus (groin) on the sidelines shortly before the tournament gets underway in France.

Germany opens its campaign against Ukraine in Lille on Sunday. Poland and Northern Ireland are also in Group C.