Both players have been ill during last week and will not be risked by Reds boss Simon Davey. Fellow defender Bobby Hassell will also miss put due to the knee injury which have forced it him out of all the pre-season friendlies this summer.
Davey is now likely to field a makeshift defence tomorrow night at Oakwell, kick-off 7:30pm.
On Reid, Davey told www.barnsleyfc.co.uk:
"Paul started feeling ill on the final day in Portugal and has not been back to the club since. He is feeling better and we expect him to train on Tuesday but he will not be ready to play against Wigan.
On Koluk, he stated:
"Rob was sick on Thursday and we will have to look at him closely when he comes in for training tomorrow morning.
"He might be ok for the Wigan game but we will take no chances".