Joey Barton is under investigation for an alleged breach of betting rules, according to Sky sources.
We understand the Scottish Football Association is investigating allegations relating to betting activity involving the 34-year-old midfielder.
It is understood the SFA is awaiting a full report from the Gambling Commission over whether Barton broke football betting rules.
We understand any alleged activity on Barton's part does not relate to any games involving Rangers or any SPFL matches.There were reports on Tuesday morning that this alleged activity relates to Celtic's recent heavy defeat to Barcelona in the Champions League, where Brendan Rodgers' side lost 7-0 at the Nou Camp.
Rangers boss Mark Warburton was asked about gambling among footballers after his side's 5-0 win over Queen of the South on Tuesday, and he said: "The players north and south of the border know the situation. There is a zero tolerance policy and that has been made very clear to them."
Barton has been suspended by Rangers for three weeks after a meeting with Warburton on Monday following a row with team-mate Andy Halliday and the Rangers boss in the wake of their 5-1 defeat to Celtic.
Previously, Warburton refused to elaborate much further on the statement issued by Rangers on Monday morning which confirmed that Barton will not return to Ibrox or their training centre at Auchenhowie for three weeks.
"What it means is what the club said in the statement; it is not for me to make any further comment other than what has been released by the club this morning," he said.
"I'm sure you can understand from my position, and the position of the club, the statement has gone out and no further comment will be made so I trust you will respect my statement on that fact."