The West Brom striker, who along with Rabbi Matondo and Tyler Roberts, was sent home after breaking a curfew at the team hotel ahead of March’s World Cup qualifier against the Czech Republic and was not included in the 28-man party on Monday, unlike the other two.
Robson Kanu, who retired from international football in 2018 but then made himself available again, scored one of the most famous goals in the nation’s football history in the 3-1 victory over Belgium as Wales made it to the last four at Euro 2016.
He is also in form having scored twice in his last three Premier League appearances for the Baggies against Liverpool and Leeds.
Manchester United winger Daniel James will also be missing as he prepares for the Europa League final, while Swansea duo Connor Roberts and Ben Cabango, Lincoln midfielder Brennan Johnson and Newport pair Josh Sheehan and Tom King are on play-off final duty with their respective clubs.
Fifteen of the men who have been working together in Cardiff since the end of their domestic seasons are included in the travelling party which headed for the Algarve on Monday and will train there until Saturday.
The camp is a final opportunity for players to stake their claim for a place in the final 26, which Page will name on Sunday.
Wales will warm up for the tournament with friendlies against world champions France at the Stade Allianz Riviera in Nice on June 2 and Albania at the Cardiff City Stadium three days later.
They open their Group A campaign against Switzerland in Baku on June 12 and face Turkey in the same city four days later before meeting Italy in Rome on June 20.
Training camp squad: Wayne Hennessey (Crystal Palace), Danny Ward (Leicester), Adam Davies (Stoke), James Lawrence (St Pauli), Ben Davies, Joe Rodon (both Tottenham), Chris Mepham (Bournemouth), Chris Gunter (Charlton), Rhys Norrington-Davies (Sheffield United), Neco Williams (Liverpool), Joe Allen (Stoke), Joe Morrell (Luton), Ethan Ampadu (Chelsea), Matthew Smith (Manchester City), Jonathan Williams, Kieffer Moore (both Cardiff), Aaron Ramsey (Juventus), Harry Wilson (Liverpool), Gareth Bale (Real Madrid), David Brooks (Bournemouth), Tyler Roberts (Leeds), Tom Lawrence (Derby), Rabbi Matondo (Schalke), Dylan Levitt (Manchester United), Tom Lockyer (Luton), Rubin Colwill, Mark Harris (both Cardiff), George Thomas (QPR).