It will top versus bottom at St Mary's on Sunday.
"The manager was saying that again this week," Kelleher told Liverpoolfc.com. "As players we know ourselves, they're a really good team. I think they've just been a bit unlucky with results and stuff.
"But they play a great style of football, they're really good with the ball and they create lots of chances. We're expecting a really tough game. I don't think we're looking at the league position too much."
Kelleher added: "We as players and the staff as well know, we're not silly. We know how good they are and the quality that these players have. I think sometimes the results don't reflect the quality that's in the actual team.
"You need to take every team in this league very seriously or else you'll end up not getting good results. We're going to prepare as if we're playing a Man City or a Chelsea or an Arsenal. For teams like that we're going to prepare the exact same and give it our all."