"I know that United are interested," the £4million signing from Rapid Vienna told media in his homeland. "My agent has established contact but that's all that I know right now.
"My agent has mentioned a figure of 15 million euros and I came to Rangers for five million euros, so it would be a big gain for the club.
"However, I would only think of a transfer in the summer. I'm fine here and enjoying every moment. The Rangers fans give me goosebumps. They really love me now.
"I am looking forward to the Kilmarnock game on Sunday. If we win that match, it will be the first title that I have won where I have been one of the key figures. I would call it my first real title."