The Austrian midfielder signed for the Latics in 2006 from SK Brann and went on to make 145 appearances for the club before moving to Hamburg via West Bromwich Albion. Roberto Martinez has decided to welcome the midfielder back as he joins the club's battle to stay up - the sort of campaign he has been a veteran of over the years.
Although the Austrian usually plays in midfield, his ability to play in defence as well will help Wigan's rather leaky backline, and he should also slot nicely into their three-at-the-back system.
Speaking about the deal, Scharner said: "It really is fantastic to be back. Wigan will always have a big place in my heart, so to be asked to come back and help the team now is something really special for me."