The pair are both in the running to be named European Player of the Year on Monday, though they will lock horns in Saturday’s Champions Cup final in Newcastle.

Saracens’ Vunipola has been declared fit, following an ankle scare, and this weekend is ready to face his mate from two years ago. And although Vunipola is senior in years, 28 to 26, and caps, 59 to 36, he learned plenty from the Irish front-rower two years ago, down under.

“He surprised me,” said Vunipola.

“He was such a big guy and his set-piece stuff was solid, but around the park, I couldn’t believe how hard he worked. I thought: ‘I think I am alright at this’. Then you see that and you are like: ‘Oh, no I am not’. So it gives you motivation to push yourself and that is what you get with good players. You are always going to learn on tours like that; it is just a question of whether you want to”.

Vunipola is regarded as an all-court prop nowadays and has taken his game onto another level, since that trip to New Zealand.

Now, he is one of the leaders of the Saracens team, alongside fly-half Owen Farrell, hooker Jamie George, brother Billy Vunipola, and centre Brad Barritt.

He has only played 62 minutes of rugby, in the European semi-final against Munster, since limping out of England’s Six Nations game with France in February. But Mark McCall, the Saracens director of rugby, has a record of pitching the prop in after a break and being repaid in spades.

“Mako’s important and is a world-class player,” said McCall.

You want to have world-class players available for these types of games. He’s one of those players who always performs well in these high-level games. It’s not just his general play and scrummaging, and all of that, but he’s a leader for us, as well. It’s great to have him.

Since Saracens learned they would be facing Leinster in the final, they have been asked about their quarter-final defeat in Dublin last year to Leo Cullen’s side.

Saracens’ answer has been that they are a different outfit this time around.

“It did hurt,” is Vunipola’s take. “It gave us a kick in the backside for the rest of the season and opened our eyes that we probably thought we were something that we weren’t.

“We had to be honest with ourselves. It was probably the best thing that has happened to us.

“Leinster showed us there is another step-up. But this weekend is a new slate. Hopefully, we can go out there and put in a better performance than we did that day.

We had done very well the last two years. But that year itself, there was a lot for us, as a team, to learn, and we did that.