The forward has been in exceptional form for Coventry this season.
The 18-year-old is instead out on loan at Coventry City where he is earning rave reviews with his incredible performances.
The England Under-19 international has scored 16 goals in 22 appearances for the League One club and yesterday he picked up his first hat-trick in professional football.
He netted three goals before half-time as Coventry ran out 5-0 winners at Crewe Alexandra.
It was obviously a very proud moment for the lad, as he showed on his Twitter account earlier today:
Proud moment today getting my first senior hatrick! Hopefully first of many! Thankyou for all the messages pic.twitter.com/JsoJQeuhNt— AdamArma (@AdamArma9) January 2, 2016
He wasn't the only one to show his happiness at the achievement on Twitter however.
Plenty of other names were pleased to see his performance.
Former Newcastle utility man Ryan Taylor sent this message whilst Ivan Toney was also happy for his team-mate:
Plenty of his current Coventry team-mates were also over the moon with his performance:
Armstrong looks set to remain at Coventry for the rest of the season after his excellent performances and Newcastle United clearly feel he is at the right club for his development.