The veteran goalkeeper signed for The Latics following his release from Fulham and former Owl John Sheridan, now Oldham boss, thinks the deal is a big one for the Boundary Park club.
Crossley came to Hillsborough on loan last season and initially excelled before January's dip in form eventually saw him replaced by Everton stopper Iain Turner.
The former Nottingham Forest and Middlesbrough stopper will be remembered at S6 fondly after his goal against Southampton - many fans will remember he came up from the back to score the equalising goal deep into stoppage time last December.