Barry Ferguson has been stripped of the Rangers captaincy and BBC Sport understands that he has played his last game under manager Paul Le Guen.
A statement from Rangers said: "Paul Le Guen has confirmed he has chosen, on this occasion, to drop Barry Ferguson for tomorrow's game.
"And the captaincy will be given to Gavin Rae."
Le Guen is not expected to expand on his reasons until after Tuesday's match against Motherwell at Fir Park.
The sensational move follows a row with Ferguson after Saturday's disappointing 1-1 draw at home to St Mirren.
Le Guen and Ferguson had also had a recent disagreement over the importance of the club captaincy and matters came to a head at a meeting on Monday.
The latest news comes after more pressure mounted on the Frenchman with Rangers sitting third in the Scottish Premier League, 17 points adrift of city rivals and reigning champions Celtic.
"The manager obviously knows that, by taking such a decision, he has put his neck on the line"Signings made by Le Guen since taking over from Alex McLeish in the summer have also failed to ignite the SPL.
But, despite league results unacceptable to many Rangers fans, Ferguson has been in excellent and inspirational form.
There have been increasing rumours of a personality clash between the captain and manager and of splits between the club's Scottish and French players.
It is the third time that Le Guen has shown that he does not accept anyone questioning his authority.
He axed defender Fernando Ricksen from the club after a drink-related incident on a pre-season flight.
And on-loan Manchester United right-back Phil Bardsley did not play again for Rangers after a training-ground disagreement with the former Lyon boss in October.
But dropping his captain comes with greater risks for Le Guen.
MY SPORT: DEBATE
Ferguson is lauded by many Rangers fans, who are already questioning the Frenchman's management credentials.
Jim Templeton, of the Rangers Supporters' Assembly, told BBC Sport: "At a time like this, it is a lift we need, not something like this happening to our one class player.
"Paul Le Guen could not have picked a worse time and I would imagine that 90% of Rangers fans will be behind Barry Ferguson.
"The manager obviously knows that, by taking such a decision, he has put his neck on the line, so the club need to come out and state why this has happened.
"If that reason is not acceptable to the fans, there will be trouble ahead.
"Making Gavin Rae captain is as strange as dropping Barry Ferguson.
"I know he has had injury problems, but making someone captain who has been unable to hold down a regular first-team place makes no sense whatsoever."
The 28-year-old Ferguson came through the young system at Ibrox before moving to Blackburn Rovers for £7.5m in 2003.
But, after two injury-hit and homesick years in the Premiership, he won a return to his boyhood heroes in January 2005.