"I knew I had a chance but until you're in the squad you always wonder exactly where you fit in," Murphy told the Irish Times.
"So far I haven't been given any indication as to where I might play.
"Obviously 15 is my favourite position but I'd play anywhere for the Lions. I think it's fantastic for Sir Clive (Woodward) - with his real rugby brain - to have all these great players to tinker with.
Murphy added: "You just have to look at the other back-three players to see the talent: Gareth Thomas, Jason Robinson, Josh Lewsey, Iain Balshaw and Shane Williams.
"But the good thing he got over to us at the first meeting is that places in the Test team are totally up for grabs."