The Reds sit top of the Premier League and Champions League tables at this stage of the season.
Alexander-Arnold told liverpoolfc.com: "That's something you have to buy in to. I think at the start of the season, a new manager, us as players, we've got to buy in to the way the manager wants to play.
"We all understand he'll make decisions, some of which not everyone is going to agree with – every lad in the changing room thinks that they deserve to start and wants to play.
"But it's having that focus of it's a team sport, we're going to need everyone and we need to be at 100 per cent.
"We've seen recently in the games that we've had lads that have come on and really helped us win games. That's what we need.
"If you're going to be successful, you need a full, collective squad that all buy in to the idea. Hopefully come the end of the season we'll all be celebrating together."