The 24-year-old looks surplus to requirements under Paolo Di Canio's regime, having previously starred under Martin O'Neill.
McClean joined Sunderland in 2011, signed by Steve Bruce, but injuries meant he never got to play under him before his departure and instead he was blooded by O'Neill.
The former Derry City man made a stunning impact and was tied down to a new-long term deal in early 2012.
However, after a brilliant debut campaign, things did not work out last season and he appears to not be in the plans of Di Canio, who is ready to let him leave after already bringing in nine new faces this summer.
Wigan have now made their move and have had a bid accepted as Owen Coyle looks to further bolster their promotion push back to the Premier League.
It is understood that at least two more clubs have an interest in McClean.