Ireland topped the group after beating France 24-9 in the Millennium Stadium last night, but the win came at a high cost.

Peter O’Mahony has been ruled out of the remainder of the tournament with a knee ligament and it appears a near-certainty that captain Paul O’Connell will follow suit.

Speaking last night after the match, Henderson said the team had expected the physicality of the game.

“From the start of the week we knew how tough it was going to be,” he said. “As we’ve seen out there, not only the starting team but the whole bench too.

“We understand that the tournament can’t be won with only a matchday XV.

"It’s going to take not even a (matchday) 23 but the whole squad to win. We need a whole capable squad to win a tournament."

But despite the injuries Henderson remained positive, saying the squad had achieved their first target of topping the group and would now move to the next phase.

"We’ve got our initial target of topping the group and we’ll look forward to Argentina this weekend."

The Ulster lock was asked about the pressure of being called on to the field earlier than expected, particularly to try and replace O’Connell.

“Definitely coming off the bench is difficult at the best of times,” he answered. “But Joe spoke to the subs during the week.

We know that when you come on you have to fit in immediately and you have to try and add something to the game.

“From my point of you I was trying to get the ball in my hands and try and make an impact defensively as well.”

“If there’s an opportunity there i’ll definitely try and rise to the challenge,” he said.

“Obviously trying to fill Paul O’Connell’s boots would be nigh on impossible, he’s been absolutely sensational for Ireland these past years.

“Trying to do what he did would be silly. You’ve got to create your own profile.”