Shalke were weakened at the end of last season when Brazilian playmaker Lincoln went to Turkish club Galatasaray while midfielder Hamit Altintop signed for rivals Bayern Munich.

"If we don't do anything, we'll be confronted with a really tough season," compained Kuranyi.

"The young players are really good, but the composition of our team is worrying," warned the German striker.

Kuranyi, whose relationship with manager Andreas Muller is reported to be strained, added: "Lincoln and Hamit have gone and we still haven't found their replacements in terms of quality."

Fresh blood has arrived at the German club this summer including under-21 Swiss international Ivan Rakitic, however Kuranyi is far from impressed.

"I want to at least win some titles but the club is taking a serious risk with these recruitments. I am fed up of settling for second place."

Schalke, last crowned German champions in 1958, had one finger on the title last season with two games remaining but were eventually pipped to the post by VfB Stuttgart.