Purse has come back into the side for the last two league games following the ankle injury to Matty Upson against Blackburn in the 3rd round FA Cup tie earlier this month and Bruce thought that his performance in the 2-1 win against the Saints was first class.
"I think thats possibly as good as I've seen him play," said Bruce.
"He relished the challenge of Beattie and his attitude has been top class."
With Upson out for at least another 4 weeks, possibly longer, Pursey has a chance to show the Blues boss exactly what he can do and maybe save the club having to buy a new defender in the transfer window.