Scharner is returning to the DW Stadium having spent more than four years with the Latics before leaving for West Brom in the summer of 2010.
Martin O'Neill asked about his availability, but didn't take the offer any further (as far as we know at SAFC-Mad).
Paul Scharner: "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."
The 32-year-old can play in midfield or the centre of defence.
Roberto Martinez: "There is no better centre-half for us to bring in than Paul Scharner.
"He knows the football club, we know him well, he has incredible experience and is a meticulous professional which means he is always in a great physical condition.
"He is desperate to come in and help the team and fight for his position. For us, it couldn't be a better option."