The former Barcelona forward netted his first Potters goal during last week's 2-1 defeat to Schalke and came off the bench to cancel out a Jordan Rhodes header with a low drive midway through the second half.
Mark Hughes, whose men are still without a pre-season win, had named a far stronger side than the XI held by League Two Burton on Saturday, with Peter Crouch partnered by Mame Biram Diouf in attack and Charlie Adam deployed alongside Steven Nzonzi in central midfield.
Crouch had the game's first real chance, his downwards header from a Phil Bardsley cross bouncing off an upright and away from trouble.
But minutes after Joshua King had sounded a warning, outjumping Marc Muniesa to head just over, Rhodes evaded his marker to glance Craig Conway's cross past Asmir Begovic.
Hughes, up against his old club, called for Bojan as part of a triple substitution and saw him make a quick impression, a jinking run goalwards wasted when Adam blazed over.
But the Spaniard was rewarded for his willing in the 68th minute, trapping a ball that Nzonzi laid into his path before rifling into the bottom corner from 20 yards.
Bojan was involved again in the closing minutes, delivering a looping ball from the right, but Diouf misjudged its flight and the draw ensued.
Blackburn kick off the new Football League season against Cardiff on Friday - watch live on Sky Sports 1 from 7.30pm.