Manager Ally McCoist warned Gregg Wylde he must learn from his mistakes after the youngster picked up a red card as Rangers earned a 3-1 win over Dundee United.
A double from Nikica Jelavic and an own-goal from Garry Kenneth sealed the victory but the only real dampener on the day for Rangers was the last-minute dismissal of Wylde for a kick at Willo Flood.
McCoist said: "I haven't seen it but I'm told that he kicked out at somebody. 10 years ago we wouldn't be talking about it, it would be nothing. Nowadays it's a sending off and that's not in Gregg's defence, far from it. He should know better."
He added: "He's a young lad, he has broken into the team and he has done well and he will continue to do well and he will continue to progress."
"But he will have to learn that things like that are not acceptable."
The win allowed Rangers to move 15 points clear of Celtic and 12 clear of Motherwell as both teams prepare to meet at Fir Park on Sunday.
McCoist added: "The most pleasing thing was the win and the three points were vital to us. We got the game we thought we would get, it was really tough. In terms of the performance, we can do miles better with and without the ball. But it's a great result because Dundee United can put you under pressure and they certainly did that."
Jelavic was initially credited with a hat-trick and former striker McCoist joked: "You can go in there and try to get the ball off him - I wish you all the best!
"I thought the third goal was an excellent goal. You're telling me it goes in off Garry Kenneth but it doesn't go in off him without Jelavic putting in a real centre-forward's desire to get on the end of a wonderful cross from Steven Whittaker.
"I saw the effort Jelavic put in to get on the end of it and unfortunately for the big defender it comes off him and goes in."
Source: PA
