Earls got a taste of what is to come in Cape Town last weekend when the red shirts appeared among the biggest crowd to date on tour, 34,176, for the win over Western Province at Newlands.
"It was great to see and hear the Lions fans last weekend and there will be more to come for the Test this week," said Earls.
"I saw four St Munchin's College shirts in the corner - it was amazing to see them in South Africa.
"I know how important the fans can be to a team. When Munster played in Clermont in the Heineken Cup it was supposed to a hostile environment, but the Munster fans were magnificent and really gave the team a boost.
"I think that's going to be the same in Durban this week. There are reports of so many Lions fans coming over for the game and it will be great to have them backing the boys."
Earls gets his chance to play full back against the Southern Kings on Tuesday, but doesn't believe he is in with much of a chance of getting into the Test team.
"Let's be fair, I've got Brian O'Driscoll playing in my position and he's in great form. It has been magnificent for me to be able to train alongside him and so many other great players here," said earls.
"But, to be honest, I'm still a bit star struck when I talk to him. When you think that at the start of the season all I wanted to do was get a few games for Munster, this is