Switzerland international Sandro Burki could be set for a move to Celtic.
Reports claim the Aarau midfielder visited the club's Lennoxtown base last week.
The 23-year-old is remaining tight-lipped on a potential move to the Scottish champions.
But Aarau's sporting director Fritz Hachler believes a deal could be concluded in the January transfer window.
"I think it is likely that Sandro will move to Glasgow," he said.
"He was in Scotland last week and we expect the transfer to go ahead."