"We've not entertained very much here at Ewood this year and we've been put in a difficult situation," Souness told Sky Sports News after the game.
"You are always thinking the worst and I had visions of the last game of the season of us going to need something against Birmingham.
"They have got three ex-players and I thought one of them would get the goal, the old Denis Law thing which beat Man United.
"Thay had a few big players missing and we had a few big names out so I'm absolutely delighted."