The tournament’s only two unbeaten sides meet at the Aviva Stadium next Sunday in a game that is expected to be decisive in the final reckoning.
Haskell played in the game at the Aviva four years ago when Ireland destroyed England’s Grand Slam dream and says his side have to beat their hosts up front to have any chance of keeping their clean sweep hopes alive.
The flanker also says England have been working on their defence after conceding three tries against Italy last time out as they are well aware Ireland will punish any defensive lapses.
“Dublin will be massive,” said Haskell. “Two wins from two each – it doesn’t get any bigger than that.
“When we get there it will be head-guard on, gum-shield in and time to work at the coal face.
“The forward battle will be key. Ireland are very physical and they love that catch tackle. They have outstanding players across the board, not just in the back row.
“It’s going to be extremely intense. We have to fix the errors in our game and make sure we hit the ground running in Dublin.
“We definitely know we can’t afford to let three tries go through as we did against Italy. We were caught short defensively against the Italians – but Ireland will be a very different kettle of fish.”
And Danny Cipriani has told Ireland that England have a mental toughness about them now they might have lacked in recent years.
Cipriani made a try-scoring return to the England side against Italy and is almost certain to be among the replacements at the Aviva.
But he says England’s victory in Cardiff in round one – when they came from 10-0 down to win – shows they do not lack for resilience while he has also praised fly-half Johnny Sexton as one of the best in the game.
“This England team is in a very strong place,” he said. “The mental resolve of the side is very good. We went down to Cardiff and were 10 points down after a few minutes, so to stick to the script and come out on top was phenomenal.
“Against Italy we knew they would bring passion and fire, and we combated that and came out on top.”
He added: “There are a lot of great fly-halves in the world of rugby but Sexton went to France, learnt a lot and is the fulcrum of the Ireland side. He is one to watch.”