The Saints coach saw his team dispatch London Irish 38-14 on Sunday to book a last-four showdown at Bristol.

 Northampton take revenge on Irish

But the New Zealander was angered by the Exiles' selection of what was effectively a second XV.

And he also condemned the tournament structure that makes Northampton travel to Bristol, even though they finished three places higher than the Shoguns in the final league table.

"How do you get players up to play that?

"We had injuries and illness all week. I had some guys on the bench who shouldn't have been there because they were ill, but they still wanted to front and be part of the contest.

"This was a poor game with poor skill levels by both teams, which probably reflected the mental approach.

"Let's take this competition seriously or not have it at all."

And he added: "I'm critical of the whole structure of the competition.

"A competition that rewards an eighth-placed team with a home semi over a fifth-placed team needs to be explained to me. I don't follow it."