But after hearing his name in the final selection, Faletau was not only on the lookout for his Welsh teammates but also Saracens front row Vunipola.
"We were just finishing training at Newport HSOB and Tom Brown was listening to it on the radio," Faletau told WalesOnline.
"I was chuffed when they said my name. It is an unbelievable feeling that has not sunk in. It is great to be in the same squad as my cousin and I was cheering more when I heard his name."
Rugby obviously runs in the family, with Faletau taking up the sporting mantle from father Kuli who played for Ebbw Vale, Pontypool and Tommawr.
But the older Faletau was calm in his praise, with the 26-cap Wales star adding: "I phoned my Dad to tell him afterwards but he does not say much. He said 'well done and I will see you when you get home'."
Faletau isn't the only Newport Gwent Dragons star in the Lions squad, however, where he is joined by flanker Dan Lydiate.
And Faletau is tipping the flanker to make an impact after battling back from a broken ankle that caused him to miss the RBS 6 Nations.
"Dan has had a few games under his belt and it is great he has been included in the Lions squad after battling back from injuries," said Faletau. "He showed what he could do last season and is probably the best around at what he does."