West Brom duo McAuley and Brunt have been key figures for manager Michael O'Neill and their loss - Brunt to groin and knee problems and McAuley for unspecified personal reasons - will severely weaken the squad. Both men played the full 90 minutes in Albion's dramatic 2-2 draw with Chelsea on Saturday.
The further absence of nine-cap Rotherham midfielder O'Connor, who has a thigh injury, leaves O'Neill with just 18 players at his disposal.
No replacements have been announced at this stage, but such a paucity of numbers makes it probable that the likes of Barnsley winger Paddy McCourt could be called up to cover for Brunt, while Hull's Alex Bruce would be a possible replacement for defender McAuley.
O'Neill would be loathe to draw on his the country's under-21 squad for reinforcements given that they have a European Championship qualifier in Italy on Thursday night, just a day before the senior game in Adana.