The central defender has missed the last two outings with a hamstring injury picked up at Watford, but now back in full training he comes into contention for the final match of the season.
Also chomping at the bit to return is David Dunn, the midfielder will be assessed on Friday to see if he can feature against his former club.
"Gael is back, he has recovered from his hamstring so that is one extra for us," said Bowyer on Thursday afternoon.
"We've one or two who will be assessed tomorrow morning, one of those is Dunny, he'll be desperate because he's a former Birmingham player.
"He's been magnificent for us in the last couple of games, he has shown how much this club means to him.
"The quality that he has got and what he brings to his team as well as his experience is invaluable to us, so if he is fit and ready he will feature that is for sure."
Tickets for the Birmingham match will be on sale at Ewood until 4.30pm Friday. Tickets are priced at £27.00 Adults, £16.00 Senior Citizens aged 65 and over and Students aged 18-22 and in full time education, £11.00 13 – 18 year olds and £7.00 Under 13s. Supporters should note that there will be NO tickets on sale on the day of the game.