VfB Stuttgart forward Cacau will sit out the remainder of the UEFA Europa League group stage after suffering a knee injury.

The 31-year-old German international tore cruciate ligaments in training on Wednesday and although club doctors hope to avoid surgery by fitting him with a specially designed brace, Cacau will be out for at least three months.

"It is a bitter blow for us, of course, and I feel really sorry for him," Stuttgart sporting director Fredi Bobic said. "Naturally, we will support him in every possible way and hope that surgery won't be necessary as he would then be out for an even longer period."

Stuttgart have only one point from two matches in UEFA Europa League Group E and lie fourth. They are at home against FC København next Thursday.