Wigan goalkeeper Chris Kirkland is struggling to be fit for the opening game of the new Premier League season at West Ham.
The England international had been expected to return to training on Monday after a recent scan on a back injury showed no serious damage, but he is now to see a specialist.
"Kirky jarred his back," first-team coach Eric Black revealed.
"He has had it scanned and he is going to see a specialist. It was a spasm - he has had these things before. We're hoping it won't be too serious."
Centre-back Paul Scharner is also a doubt due to an ankle injury sustained in the 6-0 friendly win at Barnsley last week.
Although Scharner should be fit to take on the Hammers, of greater concern are midfielder Jason Koumas and right-back Ryan Taylor.
Wales international Koumas has not made an appearance in pre-season due to a knee injury, whilst Taylor has only figured in one game because of a calf problem.