Stephen Crainey has torn ankle ligaments, a scan has confirmed.
The left-back is expected to be out of action for at least a fortnight after sustaining the injury in Saturday’s defeat by Sunderland.
It is a strange injury because Crainey can already put his full weight on the ankle and is not wearing a plaster.
He was at Bloomfield Road to watch the Manchester United match on Tuesday and said he was hopeful of a quick return.
Billy Clarke is six weeks away from fitness, which means Ian Holloway has a big decision about whether to include the striker in his 25-man Premier League squad.
Clarke ruptured a cruciate ligament seconds into the Seasiders’ first pre-season friendly at Tiverton and has spent the last six months doing rehab.