Lee Wallace has successfully appealed his red card against Annan earlier this month.
The Rangers full-back was sent off for a professional foul after bringing down Annan's Jack Steele in the penalty area.
But an appeal was submitted to the Scottish Football Association on the grounds Wallace was not the last covering defender, and a Fast Track Tribual agreed.
An SFA statement read: "Upon reviewing the incident, the match referee, Paul Robertson, stood by the awarding of a penalty kick but considered that the incident did not deny an obvious goalscoring opportunity.
"The Tribunal accepted this view and upheld the player reference, reducing the offence to a caution for Unsporting Behaviour."
Wallace is now free to play in Saturday's Glasgow derby with Queen's Park.