Liverpool will converge at the AXA Training Centre in the first week of July, though new head coach Slot will not be able to work with his full squad.
With 10 players currently at the European Championship and four others set for Copa America in the United States, they will all return later in the summer.
Regardless, Slot can expect at least 16 senior players to work with on day one of pre-season.
Salah is the most high-profile of those due back first, though his training could then be interrupted if he is called up by Egypt for the Olympics.
The Olympics’ football tournament will take place between July 24 and August 10, meaning any players involved may not return until a week before the Premier League begins.
Liverpool are not obliged to release their players, however, which could also see them block call-ups for Wataru Endo and Stefan Bajcetic, who will be back on day one.
Other first-team regulars set to report back for the start of July include Caoimhin Kelleher, Kostas Tsimikas, Jarell Quansah, Conor Bradley, Curtis Jones and Harvey Elliott.
They should be joined by youngsters Bobby Clark, James McConnell and Ben Doak, though Liverpool could face decisions over loan moves for the trio.
Fabio Carvalho, Sepp van den Berg, Rhys Williams and Nat Phillips are technically scheduled to return for the start of pre-season, but their futures are also in doubt.
That 16-man group could be boosted if Adrian agrees a new contract, while Slot is likely to turn to the youth ranks to increase his group.
Goalkeepers Harvey Davies and Fabian Mrozek, defenders Amara Nallo, Owen Beck, Luke Chambers, Carter Pinnington and Calum Scanlon, midfielders Tyler Morton and Trey Nyoni and forwards Jayden Danns, Lewis Koumas and Kaide Gordon should be in.
Liverpool will travel to the United States for this summer’s pre-season tour, with Real Betis (July 27), Arsenal (August 1) and Man United (August 4) their opponents.
Possible Liverpool squad for day one of pre-season
Goalkeepers: Kelleher, Adrian, Davies, Mrozek
Defenders: Quansah, Phillips, Van den Berg, Williams, Nallo, Pinnington, Bradley, Tsimikas, Beck, Chambers, Scanlon
Midfielders: Endo, Jones, Elliott, Bajcetic, Clark, McConnell, Morton, Nyoni
Forwards: Salah, Carvalho, Doak, Danns, Koumas, Gordon