England face Brazil and Belgium in their final matches before Southgate names his 23-man squad for the European Championships in the summer.
Branthwaite's performances with Everton have caught the eye since breaking into the Toffees' side in the early stages of the season.
Barring a suspension against Burnley, Branthwaite has started every game alongside James Tarkowski since coming into the side on the third weekend of the season, replacing the experienced Michael Keane.
As a pair, the two have played a major role in Everton having one of the strongest defensive records in the Premier League this season, despite still being embroiled in a relegation battle.
Only the runaway top three in the Premier League have conceded fewer goals than Sean Dyche's side this season, as a six-point deduction and a misfiring attack is what has seen them drop down the table.
While already an imposing figure at such a tender age, Branthwaite has also shown his capabilities with the ball at his feet, as a spectacular strike against Brighton & Hove Albion recently was his second goal of the campaign.
That looks set to be rewarded, as The Athletic claims that Southgate is to hand Branthwaite a first senior call-up for their friendlies at the end of the month.
Southgate's setup appears to have shifted to a back four, meaning there are now just two centre-back places up for grabs in the England side this summer.
John Stones and Harry Maguire are the likely options to start, but both have suffered from injury setbacks this season, while Tyrone Mings and Conor Coady also appear to be out of contention.
Branthwaite
Read on sportsmole.co.uk