Warren Gatland reckons Andrew Porter deserves a "huge kick up the backside" from Andy Farrell after dodging a yellow card in Cardiff.
Ireland prop Porter made a brilliant try-saving tackle on Jac Morgan in the first half.
But Gatland believes the Leinster man could have been sin-binned for a late tackle on Liam Williams as the Wales full-back scored his side's only try in the 34-10 defeat to Ireland.
"I’m not sure Andrew Porter needed to do that because he was clearly scoring the try," said the Wales boss.
“With Porter, if I was his coach I would give him a huge kick up backside because even though he’s made a great tackle on the line to hold up Jac Morgan, he probably needs a reminder that in a big game, those things are potentially a yellow card (the tackle on Williams)."
Gatland said he was "comfortable" with ref Karl Dickson's decisions but added that Ireland replacements Iain Henderson and Bundee Aki could also have been sin-binned.
Henderson collided with Williams as he attempted to block down the out-half's kick, while Aki was penalised for an off the ball tackle on George North.
In fact, only one player was shown a yellow card in the Six Nations opener - Williams.
"I thought the tackle on George North, he was tackled off the ball, was potentially a yellow card because it was a good attacking position and he doesn’t have the chance to clear out," said Gatland.
"Iain’s gone up there and you could argue he could have got his body out of the way.
