Stoke City are anxiously awaiting news on Dave Kitson and Ryan Shawcross after the injured pair were both sent to see specialists.
Striker Kitson and defender Shawcross were both substituted during Saturday's 1-0 win over West Bromwich Albion and initial scans have failed to reveal the full nature of their knee and back problems respectively.
"We were hoping the scans wouldn't show anything, but unfortunately both showed there is something there that needs looking into," manager Tony Pulis told the club's official website.
"We're hoping it's nothing serious in both cases, of course, but we won't know precisely what's wrong, if anything, until the specialist has given them a good going over.
"The injuries are all a bit of a mystery in both cases, it seems, but hopefully the specialist can shed some light on just what is going on.
"It's obviously a concern for us and for the players when you are in the dark, but we'll see what today brings before deciding our next step.
"Either way, both Dave and Ryan could be struggling for Saturday (against Hull City at the Britannia Stadium)."