Defender Ben Mee is set to miss the start of the season with a knee problem.
The former Manchester City youngster twisted his knee last Monday night in the 3-0 win at Cork City, and has sat out the following friendly wins at Carlisle and Tranmere.
The 23-year-old has had a scan, which has shownthe injury is not serious, but he is a big doubt for the visit of Bolton Wanderers to Turf Moor a week tomorrow.
Marvin Bartley, yet to feature in pre-season, is also likely to be unavailable with a niggling hamstring injury.
Michael Duff was the only other absentee at Prenton Park on Tuesday night, with a knock sustained at Carlisle.
But Kieran Trippier returned after a minor hamstring strain.
Dyche said on Tuesday night: “Ben had an awkward knock in Cork.
“It could be 10 days to a couple of weeks before he’s ready. We’ll wait and see on that one, we’ll have to monitor it wisely.
“He’s had it checked out with a scan so we know it’s nothing major.
“He’s an honest lad, he’ll put his foot in and challenge and he can be a tough competitor. Sometimes that has a downside.
“He’s been very unlucky. The one at Cork looked like it maybe was a bit late and he’s been nicked across his ankle which in turn has twisted his knee slightly.
“It’s nothing serious but it’s still sore and it still has to be dealt with.”
On Bartley, he added: “We didn’t think Marvin’s hamstring would take as long but he’s had to take his time and make sure it’s right.
“It’s a shame because he was looking well and fit and strong. We’re surprised it’s taken a bit longer but hamstrings can be funny like that. He’s moving well now but he’s not there yet.
“And Duffo had a niggle on Saturday so we made sure we got him off quickly.”