Oldham recorded their first pre-season win with a 1-0 victory at non-league Mossley on Tuesday night.
A 16th-minute goal from an unnamed trialist settled a scrappy game in which Latics again fielded different line-ups in each half.
Warren Feeney and Ryan Brooke did not feature after being pencilled into to play the full 90 minutes in Wednesday's behind-closed-doors friendly at Blackburn, while James Tarkowski missed out with a toe injury.
Boss Paul Dickov said: "I wanted to have a good look at the two lads (trialists) up front at Mossley.
"Warren and Ryan will play the full game at Blackburn. Again it will primarily be a fitness exercise, but it will also provide another opportunity to work on things behind-closed-doors away from everybody."