Jordan Jones has apologised to Celtic's Moritz Bauer for the challenge that earned the Rangers winger a red card in Sunday's Old Firm game, according to former team-mate Gary Dicker.
Northern Ireland winger Jones is out of his country's upcoming double-header after injuring himself with a wild lunge at the Austrian in added time.
Jones left Ibrox on crutches after the game, which Celtic won 2-0.
"He's waiting for scan results," said Kilmarnock captain Dicker.
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"Hopefully it won't be as serious as he thinks it is. He spoke the right-back at Celtic and apologised."
Jones played alongside Dicker for three years at Rugby Park before moving to Ibrox this summer on a pre-contract deal signed in January.
The 24-year-old made his Old Firm debut as a second-half substitute on Sunday and was criticised by manager Steven Gerrard for his sending-off, but Dicker is sure his friend will learn from the experience.
"I spoke to him today to see how he was," the Irish midfielder added to BBC Scotland. "It can be a lonely place. He was pretty down, which is natural.
"It's frustration. I don't think he was doing it to get a round of applause or hurt someone. It can mess with your emotions, it's a big occasion, but he'll learn from it."