Take a look at how the Reds can line up with the 24-year-old but bear in mind that there will be other arrivals at Anfield this summer.
A left-sided no.8
Historically, Jurgen Klopp does not really change formation to accommodate new signings — the German rather expects new arrivals to fit in his current system.
If the boss sticks with the 4-3-3 formation, Mac Allister could easily slot in on the left side where he normally plays — a role that Thiago performs when he's fit.
Lile the Spaniard, Mac Allister is a really good passer but he should also be a much bigger goal threat, something the Reds have lacked from midfield.
A double pivot
Mac Allister is no stranger to playing in a deeper role — he has performed there both for the club and country even though he's not a holding midfielder.
The Argentine prefers to receive the ball in a higher position and carry it forward before making a pass. He will need a proper defensive midfielder alongside him.
This is a role Mac Allister has been employed in recently — and he has shone in it. This season, the 24-year-old has scored a whopping 10 goals for Brighton.
Of course, this variant will require a tactical change. Klopp turned to this formation on rare occasions this season, but it still looks very much like a Plan B.