Rangers midfielder Joey Barton has been signed off with stress as negotiations on a severance deal continue.
The 34-year-old Englishman was told to return to train with the under-20s last week following a six-week suspension for a training ground row with team-mates in September.
The former Burnley and Manchester City player has not been at training since Thursday.
Barton has made eight appearances for Mark Warburton’s side this season.
The once-capped England international left Burnley under freedom of contract at the end of last season, signing a two-year contract at Ibrox.
But he was suspended from the Scottish Premiership side following a training-ground row with team-mates including midfielder Andy Halliday in September.
It came after Barton and Halliday played in Rangers’ 5-1 Old Firm defeat, the club’s biggest loss to their local rivals since going down 6-2 in August 2000.
The result prompted discussions, which Barton claimed “involved some sharp disagreement”. Barton later apologised for “overstepping the mark”.
Barton is also facing Scottish FA charges for breaching betting rules. He was charged with placing 44 bets on games between 1 July and 15 September.