Danny Graham won't be available for Tuesday night's match against Reading.
Having undergone a minor groin operation during the international break, the striker is stepping up his recovery, but tomorrow's game at the Madejski Stadium will come too soon.
"The medical department haven't told me that he is fit," said boss Tony Mowbray on Monday morning.
"He hasn't been training really, he was on the grass at the end of last week just doing some very easy side-foot passing, just testing it out really.
"He needs to get some more robust training in, he needs to join in with the squad and he hasn't done that yet so he won't be travelling with the group for Tuesday's game."
Other than the usual bumps and bruises, there were no further knocks picked up at the weekend at Brighton, so Mowbray expects it will be the same squad that will return south.
"It is a quick turnaround but the medical department don't appear to have any concerns," he added. "So it will be the same squad travelling to Reading trying to get the win that we need.
"They are all working hard, it is a good group to work with, the players are very much on board working really hard."
Fans who haven't yet purchased tickets for tomorrow's match have until 11am to get them from Ewood on the day of the game.
After that they will be available on the night at the Madejski Stadium, from the South Stand Ticket Office from 6.30pm. Prices are £23 for Adults, £16 for 65 & Over, £13 for 18-24 years and £8 for Under 18s.