The Japanese playmaker fears he will fail to recover in time from a knee injury that has been troubling him for the last few weeks, and he could even be out for the next fortnight.

Asked if he would be ready to face AC Milan, Naka said: "If I could play, I would like to. It doesn't hurt when I am walking, but it does when I run and shoot.

"There are still many games in the season, so I would like to cure this injury properly."