Eddie O'Sullivan reckons Ireland fly-half Johnny Sexton had an "off-day" against Wales over the weekend, but says that wasn't the reason Joe Schmidt's side were comprehensively defeated.

Ireland's Six Nations bid hit a speed-bump in Cardiff with a 23-16 loss on Saturday, and the previously imperious Sexton was out-of-sorts as the hosts dominated at the Millennium Stadium.

"I thought he had an off-day for sure," former Ireland boss Eddie told Ivan on Newstalk's Breakfast this morning. "He wasn't his normal self. He looked at bit uncomfortable on the ball.

"He didn't really have the kind of swagger we associate with his game.

"I don't think that was the difference between the teams. Wales were very dominant physically and in defence ... they also were very smart ... they took away the space from Sexton."

Listen to Eddie on Breakfast here:

Despite a listless performance by Schmidt's side, Eddie isn't expecting an overhaul for the trip to Edinburgh on the Six Nations' final day.

"I don't think there'll be too much changes in personnel, if any," he said, "but I think maybe a change in strategy."

The Biarritz boss also has a surprise tip for the championship come Saturday: "Wales are in the driving seat," he said.

"I say that because they're playing Italy who at the end of the Six Nations are often a bit bedraggled, carrying injuries, so they'll struggle ... it's doable for Wales."