Blues coach Laurie Daley took responsibility for Nathan Merritt's defensive faults in his Origin debut – but stopped short of guaranteeing him a place in the series decider.

Merritt, one of the game's great tryscorers, was caught out of position on two occasions when Queensland winger Darius Boyd crossed twice.

Defensive lapses: Nathan Merritt. Credit:Getty Images

However, Daley said that Merritt was operating under instructions to push in-field to mark Maroons centre Greg Inglis and had left Boyd unmarked.

''That wasn't Nathan's fault, it was us – it was me,'' Daley said.