The 19-year-old midfielder is currently at Bolton but is set to feature as a substitute when Oldham's reserve-team face Wrexham at Chapel Road on Wednesday afternoon.
Liam Irwin has been capped by the Republic of Ireland at Under-19 level.
His father Denis was signed by the Latics on a free transfer from Leeds in 1986. Four years later he was sold to Manchester United for £700,000 and became one of their most decorated players.
Oldham last week