Wednesday 24 May 2017 13:01, UK
Brian O'Driscoll believes the loss of Billy Vunipola is "astronomical" for the British and Irish Lions.
The England international looked to be a certain Test starter at No 8 but he has been forced to withdraw from the squad with a shoulder injury, with James Haskell called up to replace him.
Vunipola's cousin, Taulupe Faletau, has emerged as favourite to start at No 8, while CJ Stander and Ross Moriarty are also options at the position.
But O'Driscoll feels Vunipola was the one player Warren Gatland could not afford to lose and it makes the already unenviable task of taking on the All Blacks in New Zealand that bit more difficult.
"The loss of Billy Vunipola is absolutely astronomical," O'Driscoll told Sky Sports News HQ.
"If you had to pick one player [for the Lions] not to have lost it would have been him. Faletau is in good form but Vunipola is the best player in the world this year.
"His ball-carrying would have been vital so it just seems like another stumbling block and it's going to be an even tougher task.
"I think Farrell and Sexton will be really important, probably together, but definitely on their own.
"A talisman now like Faletau, coming in and playing No 8 - as I am sure he probably will - will have to have a huge tour.
"It is all about go-forward [ball] down in New Zealand. You have got to match them at their own game so you need as many ball carriers as you can get. You need those guys performing at the top of their game."
