Liverpool captain Virgil van Dijk concedes they go into new season with major questions surrounding the squad.
Six senior players have left this summer, including captain Jordan Henderson.
"I can definitely understand it [fans' negativity] in some ways but I'm not a very negative person," Van Dijk said.
"But obviously when a lot of players are leaving, when your captain is leaving, your vice-captain is leaving, and at the moment there are only two incomings.
"And the way we have been playing, in possession really good but defensively when you concede goals it's not as good, I can understand some people having doubts."
He added: "It will be very tough if we look at the teams around us, but we want to be up there again, we want to be challenging again.
"We have to be confident, we should be confident and we should still be learning each and every day. There have been characters leaving, players who have played a big part in the success, but others have to step up.
"That's a nice challenge in my opinion. We should be excited. I'm very excited, so let's give it a go."
