United have lost two of their last three games, but Davis has insisted that they will not be easy opponents.
"For us, I think it is a game to look forward to. I am sure Man United won't take us lightly after the start we've made," Davis told Sky Sports News.
"These are stadiums you want to play at and players you want to test yourself against. I think it is the biggest test. Every Premier League game is a test because you're coming up against top players, but I think coming up against Man United, obviously being champions, is a game we can look forward to.
"We can go there, try to play the way we can, and if we do then we are more than capable of getting a result."
Southampton currently sit fourth in the Premier League, while United occupy ninth place.