Date of birth
Tony Mowbray's first signing of the January transfer window, Adam linked up for the second time in his career with the boss.
The exciting youngster, who turns 21 in February, recently completed a loan spell at Championship side Bolton Wanderers and will now look to gain promotion to the second tier with Rovers.
Having joined boyhood club Newcastle at the age of nine, Armstrong progressed through the ranks and made his Premier League debut in 2014, aged just 17 years and 33 days.
The following season saw Armstrong loaned out to Coventry, where he played under Rovers manager Tony Mowbray and made a flying start, scoring five goals in his first five games.
He was later named in the PFA's League One Team of the Year after finishing the season with 20 league goals and was subsequently rewarded with a new four-year deal at Newcastle.
Armstrong gained further first team experience on loan at Championship club Barnsley last season, before spending the first half of the current campaign with Bolton.
The forward has also made an impact on the international stage and was part of the England side which won last year's Under-20 World Cup in South Korea.
Armstrong scored in the Three Lions' opening game against Argentina, going on to make four appearances in the tournament alongside fellow Rovers loanee Harry Chapman.