Reports have previously linked Janko with a move to Blackburn Rovers.
“I was in Glasgow three times in January talking to Celtic about Marc, and the player himself spent one-and-a-half days looking about the club,” George Stanggassinger told the Daily Express.
“The fact Celtic had done everything properly and were very serious with their proposals impressed Marc. We’ll see what happens in the summer.”
He added: “Celtic had watched Shikabala a few times. It remains possible for a move in the summer.”
