Robbie Henshaw admitted "not knowing the rules" regarding the penalty that cost Ireland a crucial try against Wales on Friday.
Ireland trailed 15-9 with 10 minutes remaining at the Principality Stadium when hooker Rory Best went over at the back of a rolling maul.
However, referee Wayne Barnes was forced to disallow the score as centre Henshaw had entered the maul ahead of the ball.
Ireland went on to lose 22-9, a defeat that ended their hopes of winning the Six Nations title, and Henshaw was contrite in his assessment afterwards.
"It's just me not knowing the rules," he said. "I thought it was turning so I thought [Best] was going to break out so I was going to latch on and try get him over.
"I came in quite fast as well and didn't have time to readjust. I put my hand up."
England's subsequent win over Scotland on Saturday saw Eddie Jones' side retain their title - a clash with Ireland in Dublin standing in their way of a second successive Grand Slam and a record-breaking 19th straight Test win.
It was Ireland who ended New Zealand's run of 18 consecutive victories in Chicago last year, and Henshaw wants his team to be the party-poopers once again.
"To end England's winning streak is a great motivation for us," he said.