While Alexander-Arnold has recovered, Jota was sent back to Merseyside early by Portugal for a muscle issue that prohibited the forward from playing or training with his country.
But with the 23-year-old back in the mix, it, in turn, boosts the midfield options for the Reds.
Milner can be thrown back into the mix alongside the likes of Jordan Henderson, Naby Keita, Alex Oxlade-Chamberlain and Curtis Jones – following his own comeback from a groin issue, while Fabinho and Thiago are expected to miss the clash.
With a handful of Reds in action on Tuesday, fingers will be crossed that no new injuries arise ahead of the squad reassembling ahead of the eighth league game of the season.
Possible XI vs. Watford: Kelleher; Alexander-Arnold, Matip, Van Dijk, Robertson; Henderson, Jones, Keita; Salah, Mane, Firmino