Graffiti referring to the 1971 Ibrox disaster and former Rangers player Ian Durrant, who in 1988 suffered a major knee injury against Aberdeen, was reportedly scratched into the paintwork outside a hotel in the early hours of Sunday. There was tape covering parts of the bus as it arrived at Pittodrie.
A Rangers spokesman said: “We are disgusted and disappointed by this act of vandalism. ‘In particular, the reference to the Ibrox disaster in which 66 people lost their lives was particularly vile.
“This sort of behaviour has no place in civilised society. The incident was immediately reported to Police Scotland and we will assist them with their enquiries.”
Rangers’ first visit to the Granite City in more than four years was expected to be a fiery affair, and opposing fans had to be separated by a line of police and stewards as objects rained back and forth early in the first half.
Aberdeen scored first, just 22 seconds into the second half as Rangers switched off, allowing Johnny Hayes to pounce.
Andy Halliday equalised with a penalty 13 minutes from time but Maddison proved to be the match winner after referee John Beaton judged James Tavernier to have fouled Hayes.
Rangers striker Joe Garner said: “I think we have got to be very frustrated really. We got back into the game at 1-1. Tav has made a good tackle, the referee has given a foul and fair play to the lad he has put it in the top corner.
“We have watched it back in there and it is clearly a good tackle. He has got the ball. But the referee has made his decision and we have got to get on with it. We have got to take the positives out of the game and go again.”