And Lions assistant coach Warren Gatland admits their timing could not have been better on the eve of their ten-game tour in South Africa.
"The Leinster lads have turned up feeling on top of the world after their Heineken Cup victory," said Gatland.
"That sort of positive attitude will hopefully rub off on the rest of the squad.
"Obviously we have to be mindful of the fact that they, along with the Leicester players, have played a lot of rugby recently so we will have to manage that in the first week in South Africa.
"We've obviously been looking forward to this moment. There's a bit of trepidation because now the real work starts, but it's very exciting.
"The biggest challenge in the first week is settling into a new country, finding our bearings and getting our preparations in place for that first game. Once we do that, we'll be up and running for the tour.
"The most exciting thing for this squad is that right now, there is only a couple of players you could hang your hats on for a starting place in the first Test. There's a great opportunity for everyone. Anyone could play themselves into selection."
The Lions have flown to Johannesburg with three new faces from the original selection with Scotland hooker Ross Ford, England flanker Tom Croft and the latest addition, Wales playmaker James Hook, on board.
"There have been a few injuries, but it hasn't been difficult at all this week," added Gatland.
"We were always prepared to lose a few players after the original selection, though it probably has been a few more than we thought. However, it's easier to deal with that while we're at home.
"I'm obviously gutted for the boys who have been forced to pull out after selection. You have to feel for guys like Tomas O'Leary, Tom Shanklin, Jerry Flannery and Alan Quinlan and we're still confident Leigh Halfpenny will rejoin us.
"But obviously that opens a terrific opportunity for the likes of Ross Ford, James Hook and Tom Croft."