There is also a nod for ex-Man City prodigy Jadon Sancho, 18, who is going great guns with Borussia Dortmund this season - thus potentially making him the first player born post-Millennium to play for England.
What has happened is that, in a little more than 12 months, Sancho has made 21 appearances for Dortmund, including two starts in the Champions League this season, and has performed so impressively that yesterday he was named in the England squad.
Reports suggested he would be handed his first U21 call but an impressive performance and an assist against Monaco on Wednesday changed Southgate's mind.
Derby midfielder Mount, 19, was watched by Southgate during their Championship match against Blackburn after impressing on loan from Chelsea.
Scotland worldwide and Fulham midfielder Tom Cairney has also been linked with a switch to England, but manager Alex McLeish said there is "nothing sinister" in his absence from the squad named this week. Two of them have returned to the group after injury: Watford's Nathaniel Chalobah and Tottenham's Harry Winks.
Gareth Southgate says the "big call" to select Borussia Dortmund teenager Jadon Sancho aligns with England's current philosophy.
Chaotic scenes in quake-hit Indonesia as bodies lie unclaimed
In the hills above Palu , volunteers are working to dig a mass grave , big enough for thousands of bodies, according to the BBC . Many people were trapped and buried under collapsed houses. "So, on this issue, we can not pressure them to hold much longer".
"We've got a few injuries in the midfield in particular - Dele [Alli], Jesse [Lingard] and Ruben [Loftus-Cheek] have been missing - and Fabian Delph, so there is an opportunity there".
Southgate has made a strong impact since taking over from the sacked Sam Allardyce in 2016, evidenced by England's performances at Russian Federation 2018, when the Three Lions reached its first World Cup semi-final since 1990.
"But we think they are performing well with their clubs, they're confident players".
Jadon's is an unusual story. "He's started two Champions League games for Dortmund and he's had a really big impact from the bench in their league matches so that's been a really fearless decision from him to go and seek his opportunity".
"He's a player that is explosive, is really creative in the final third, and has had a big impact in terms of assists in the matches he has played, can score goals and has had a big impact in our junior teams in the last couple of years".
Mason's situation is slightly different.
Only nine have scored for England.