Gareth Southgate will trim his initial 33-man group to 26 players on Tuesday after making final fitness checks on those involved in Saturday's Champions League final between Chelsea and Manchester City.
Sources have told ESPN that should right-backs Reece James and Kyle Walker both indicate they have come through the Champions League final in Portugal unscathed as expected -- neither suffered obvious fitness problems to the naked eye -- Alexander-Arnold will be left out of Southgate's final squad.
A third right-back, Kieran Trippier, is also expected to be selected. The news will come as a bitter blow to Alexander-Arnold, who had been a doubt for the squad ever since being dropped for the March triple-header against San Marino, Albania and Poland.
The defender responded by producing a strong end to the campaign at Liverpool as Jurgen Klopp's side rallied to secure a Premier League top-four finish on the final day of the season earlier this month but ultimately it is unlikely to prove enough.
Alexander-Arnold's hopes had been raised after he was included in Southgate's 33-man team, a number which reflected both a series of injury concerns and the uncertainty created by three English teams contesting the two major European finals.
Southgate is keen to give players involved in those games around a week off to recuperate with sources claiming the Chelsea and City contingent are due to report on Friday. England play two warm-up games in Middlesbrough this week: against Austria on Wednesday and Romania on Sunday.
UEFA have set a deadline of 11 p.m. on Tuesday June 1 for countries to name their final 26-man squads, however, and preliminary medical checks will therefore be done on those players prior to joining up with the group.
Alexander-Arnold has cemented his status as one of the game's brightest talents, reaching successive Champions League finals with Liverpool -- winning the 2019 version against Tottenham -- while also ending the Merseysiders' 30-year wait for a Premier League title last year.
Yet he has seemingly never entirely convinced Southgate, having amassed just 12 caps since making his debut against Costa Rica in June 2018. Now it appears only an 11th-hour injury will prevent him missing out on playing in his first European Championship.