The 45-year-old German, who played for City for four years in the 1990s and was inducted into the club's Hall of Fame in 2009, makes no secret of his "great bond with City" which was strengthened when he was diagnosed with cancer in 2003.
Rosler developed non-Hodgkin's lymphoma, a cancer that attacks the lymphatic system, and at one point was only given months to live, but in his autobiography published last year he said hearing that City fans were cheering his name had a huge impact on his recovery.
In a TV interview on the Manchester City website (www.mcfc.co.uk) he said that his return to the club will be an emotional one, but he has a professional job to do.
Wigan go to City as FA Cup holders having upset the odds to beat them in last year's final when Roberto Martinez was managing the club and Rosler says his split loyalties will be put to one side for 90 minutes.
"We want to produce a result that makes our supporters proud and hopefully we can achieve that. If we do what everyone else does against City we will be beaten, so we have to do something different. We cannot park the bus.
"Hopefully we can find the tactics and the right team selection and get the result."
Rosler played for City for four seasons from 1994 and was leading scorer for three successive seasons from 1994-95 to 1996-97. In all he scored 64 goals in 176 matches.
"I have never made a secret either as player or as a manager of my great bond with City," he said.
"But I am coming back as the manager of Wigan Athletic, a fantastic football club, and have a professional job to do."
Wigan's victory last May was one of the greatest FA Cup final upsets for years but came a few days before they completed an unwanted double by becoming the first club to win the FA Cup and get relegated in the same season.
Rosler was then manager of League One Brentford, who narrowly lost out on promotion to the Championship (second tier) last season.
He left Brentford for Wigan in December and has guided the club to sixth in the Championship, with a place in the promotion playoffs a real possibility.
They have won their last four league matches and take on a City team who put the memory of their FA Cup final defeat to one side last weekend when they returned to Wembley to win the League Cup final against Sunderland.
As Wigan proved against City last year upsets do happen and as Rosler himself proved by battling back from illness, the odds can always be overturned.
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