Celtic boss Ronny Deila says keeping his best players will take priority over acquisitions in the transfer window.
Chelsea striker Fernando Torres is understood to be set for a return to Atletico Madrid, according to Sky sources.
The Reds have been tracking the 18-year-old for some time, with contact having been made in the past.
Hansen is due to spend a week working with Liverpool's reserve side, as he looks to catch the eye of the Reds' coaching staff.
He is currently back-up to the more experienced Martin Hansen at Viborg, but is considered to be a hot prospect for the future.
"I look forward to trying to impress," Hansen told Viborg's official website.
"It will be a great experience."