German legend Lothar Matthaus believes Chelsea could sell Michael Ballack in the summer.

"At Chelsea Ballack is just present rather than right in the thick of things. He is a nominal player at the big London club - that is not an insult," Matthaus wrote in Sport Bild.

"The squad is packed with top stars. To establish yourself as a leading player there is hard. Ballack has not managed it.

"He is always in the first team. The question is only: For how much longer?"