Ex-Liverpool fullback Alexander-Arnold left for Real Madrid over the summer in a Bosman transfer. And McAteer, who played in a similar role as the England international at Liverpool, believes Salah is suffering in his absence.
He explained to Tribalfootball.com: "I just think there's lots of variables in what's going on with Salah. I think he's lost his partner with Trent. I think statistically, he's not had as many passes from the right-back as what Trent provided.
"So, whoever has played right-back to what Trent's numbers were, he's not had as much of the ball from that area. I think tactically, things have been a little bit difficult for him. His start position has been a little bit difficult.
"I don't think Liverpool have kept the ball as well as what they've done last season. So, I think defensively, he's had to do a bit more work. So, his start position is possibly different than what it was last season.
"He's had a focal number nine to deal with. He does predominantly play with a false nine, where there's a lot more fluidity at the top end, and he can drift inside.
"He can link up with the forward. Now, he's having to link up with the likes of Wirtz. He's got Isak ahead of him or Ekitike ahead of him.
"He's found himself becoming more of a provider rather than a goal scorer. Again, the scrutiny on Mo Salah is second to none. He's looked at as one of the best players in the world."
Kerkez struggles
Meanwhile, on the wing-back position, McAteer has been watching the progress of summer signing Milos Kerkez with keen interest.
Kerkez, after the defeat to Manchester United on Sunday, was removed by manager Arne Slot for Andrew Robertson for the midweek Champions League victory at Eintracht Frankfurt.
For McAteer, it was the right call by Slot, believing the Hungary international needs time to adjust to the step up from his time with Bournemouth.
McAteer, speaking to Tribalfootball via casinobernie.com, said: "I just think Kerkez is struggling with confidence and his role. I think he's struggling tactically. I think at the moment the job is slightly too big for him. He seems a little lost
"It’s one thing playing for Bournemouth, it's another playing for Liverpool. The expectation is enormous, and you feel it straight away. There's no room for error at Liverpool; you're performance is scrutinised by just about everybody.
"So I actually think it would do him a favour to take him out of the team and give him a moment to sit and watch and gain an understanding of what is required from the manager’s tactics.
"Now every footballer wants to play every game, but I just think at the minute it might be the wise thing to do. Listen, Jürgen Klopp did it to Andy Robertson. Andy Robertson came in and played four or five games and was taken out of the team; he just didn't adjust quickly enough for Jürgen, so he was taken out. Trent was in and out of the team until finally, the penny dropped. With Robertson, finally, the penny dropped, and look what happened, they became the two best full-backs in the world.
"There were lots of players who Jürgen Klopp did this too, the penny didn't drop that quickly, and he took them out of the team, and then they were back in 2,3 games later. You know, he's there long-term, Kerkez, it will do him no harm just taking him out of the firing line at the minute, and play Andy Robertson, just settle everything down."
About relationships
Indeed, McAteer is confident Liverpool will find consistency and things will "settle down" once their summer arrivals fully adjust to working with eachother.
Revisiting his own experience with Liverpool, he explained, "Again, it's about forging relationships, but to forge a relationship, you've got to stay in the team, and you've got to find consistency in not only your own performance but in your relationships with other players around you. Relationship with your goalkeeper for the right back is important, you've got to know where he is positionally, and you've got to know when to either play the ball back to him and when it’s right to receive the ball off him. Communication is key.
"You strike up that relationship and then you have your centre-half, you've got to know he's covering, you're centre-midfielder, when you push into an attacking, sort of an advanced role, your centre-midfielder now comes into play because if you lose the ball high up the pitch, it's your centre-midfielder that comes across to cover you, which is what Jordan Henderson did brilliantly for years with Trent.
"So, you've got to strike up a relationship with your centre-forward because you've got to know if he wants it in behind or into feet, and that was like the relationships I had with Jamie Redknapp, Steve McManaman or Michael Owen when he got in the team.
"Michael didn't want the ball into feet; Michael wanted the ball just bent into the channel. Understanding his movement was crucial. So, you've got to forge that relationship with him. You get the ball, you look up, and he's off, bang, you play the pass.
"Robbie Fowler wants the ball in the box, you get to the by-line, you don't cut back, get it onto your weaker foot, you put the ball in first time because Robbie's going in first time. You know Jamie Redknapp's inside, so when the ball comes to you, your first look inside is Jamie's there, you have trust in your teammates, you know instinctively they are there. But defensively, the biggest thing for me was Mark Wright behind me.
"I knew where Mark Wright was 100% of the time. Communicating and positionally, and I have the trust to venture forward knowing he was on the cover, should things break down."