Butland's defiance helped take City's unbeaten away record to three games after Ruben Rochina opened the scoring for Rovers with an early penalty.
Despite being under pressure for the early stages, Blues hit back almost instantly when Marlon King pounced after a Nikola Zigic shot hit a post to notch his second goal in as many games.
But pointed to Butland's display Clark "He can be anything he wants. He is improving all the time. In the last few weeks he's looked what he is - top quality and a future international goalkeeper."
Despite Birmingham failing to win at Ewood Park in 19 attempts, Clark was pleased with the latest effort, describing the penalty as a wake-up call to his side.
He said: "We started the first half quite average and I'm glad the penalty happened when it did because give us a bit of a wake-up call.
"We showed great character when it's easy to buckle and finished the first half on the front foot and maybe could have gone in at half-time in front, and we started second half well.
"We defended well as a group and towards the end we had some good situations where we could have nicked it."