The left-back sustained the problem during the second half of Burnley's 1-1 Premier League draw with Newcastle United on Tuesday, and was carried from the field on a stretcher.
Dyche was unable to give a definitive update in the immediate aftermath of the game, but revealed in a press conference on Thursday that the news was possibly worse than first feared.
"Stephen Ward is not as good as we'd hope," he said. "We thought it might just be soft tissue, but it's a bit more than that.
"We think it's a bone injury and we'll know more when we investigate it further.
"He will see a specialist tomorrow and we'll then have more clarity to the news."
Ward will certainly miss Saturday's trip to QPR, as will Michael Duff, who continues to struggle with a calf problem picked up in last month's 2-1 win at Stoke City.
There was better news on striker Sam Vokes, though, who ruptured his anterior cruciate knee ligament in March and has been in rehabilitation ever since.
The Wales international has scored three goals in two appearances for the development squad over the past two weeks, and Dyche is pleased with the way the 25-year-old is progressing.
"I've said all along that Sam needs to get fit and well both physically and mentally," he added. "He's certainly looking that at the moment and there's more to come.
"He's enjoying his journey back to full fitness and he's on the right pathway, that's for sure.
"He's getting sharper and fitter and he's been training with us all the time for a number of weeks now.
"To be honest, his recovery has been aligned with the specialist, physios, sports scientists and himself as well.
"He's feeling he's in a good place at the minute and where he is beginning to get closer."
