The 21-year-old Romanian internationalist, who is the son of the legendary Gheorghe Hagi, has also played for Fiorentina in Serie A and Viitorul Constanta in Romania.
Manager Steven Gerrard told the club website: "We are delighted to be able to add Ianis to the squad of players for the second half of the season. We have been scouting him for some time and it was clear that he has the quality to help to make a difference to the team.”
