Celtic midfielder Thomas Gravesen's Parkhead future is in doubt after the player's agent revealed the Denmark international is unhappy with a lack of first-team action.
Gravesen, 30, began the midweek Champions League last 16 clash with AC Milan on the substitute's bench and hasn't started a domestic game since late January.
"It can be difficult for footballers who have ambitions to accept these things," agent John Sivebaek told the Scottish Sun.
"Sometimes you have to - then look at your future over the next six months or year.
"Thomas loves Glasgow and is happy with Celtic but he doesn't know why he is out of the team at the moment.
"It is a bit too early to conclude things. But, of course, Thomas won't accept being a substitute forever."