User blog comment:FairyRaven/Fairy Tail Chapter 369: The Place Prayers Reach, Review and Commentary/@comment-3075024-20140131175725/@comment-7418318-20140131200715

Kagura was trying very hard to kill Erza and Erza naturally had to fight hard to stay alive against that onslaught. While they did occasionally lash out at Minerva to keep her in check, they concentrated mostly on each other. Thus Minerva wasn't really fighting on par with either of them.