The Owls boss got the news on Friday that JP McGovern will be out until October with a back problem - an injury which nearly ruled him out of the play-off final against Hartlepool.
Drissa Diallo limped off at half time against Stocksbridge on Thursday, as did striker Barry Corr while Paul Heckingbottom missed that game because of a hamstring strain.
Adam Proudlock is hoping to play tonight against Grimsby but he is still on the road to recovery from his broken leg.
Other players who have spent the pre-season getting fit are Steve Adams, Craig Rocastle and Graeme Lee but are expected to be ready for the start of the season.
If international clearance is acquired in time for tonight's clash - Hungarian left-back Zoltan Vassas should play a part against The Mariners, as should Patrick Collins.
Forgotten man Richard Evans may also take part after returning from a trial with Colchester.