The Jamaican-born midfielder scored seven goals in 20 appearances for Villa's U21 team during the 2012-13 campaign.
He also got his first taste of senior football during a loan spell with eventual League One play-off winners Yeovil.
Johnson made five appearances for the Glovers.
The previous season saw Johnson feature in all but one of Villa's fixtures in the title-winning reserve campaign, as well as making the first team bench for six Barclays Premier League games.
In the reserve ranks, Johnson once again demonstrated his ability to supply goals from the central ground.
He found the net five times including a wonder strike in a 3-1 defeat against a Manchester United side featuring the likes of Phil Jones, Chris Smalling and Tom Cleverley.
That scoring knack was also replicated on the European stage during Villa's run to the quarter-finals of the NextGen Series.
Johnson was the only player to feature in all seven of the club's NextGen games and he managed three goals in the process.
Those strikes came in home and away wins against Fenerbahce and in a 3-2 defeat by Rosenborg in Trondheim.
Johnson's fine form continued beyond the end of the regular season when he skippered Villa to the final of the Hong Kong International Soccer Sevens.
As well as bagging five goals in the competition, he walked away with the Player of the Tournament award.
Followers of Villa's development sides were already aware of Johnson's potential following his whirlwind 2010-11 campaign.
Extra responsibility was placed on Johnson when U18 coach Tony McAndrew handed him the captain's armband.
As well as leading Villa to the Barclays Premier Academy League Group B title, he was an inspiration during the FA Youth Cup campaign.
A trademark left-foot strike from the edge of the box in round four against Peterborough crowned a true captain's performance and ignited a cup run that would see the young lions reach the semi-finals.
If his season wasn't action packed enough already, Johnson also made 13 appearances for the reserves and signed a one-year contract extension.
By the time he penned his new deal in February the man known as DJ to his team-mates had already caught the eye of manager at the time Gerard Houllier.
The Frenchman had no hesitation in calling upon Johnson to make a surprise appearance amongst the substitutes for the Carling Cup tie against Burnley in October 2010 after Stephen Ireland's late withdrawal through injury.
He kept his place on the bench for the next two Barclays Premier League games against Blackpool and Manchester United.
Despite his meteoric rise to the cusp of senior stardom, Johnson's true golden moment came in the final U18 game of 2010-11 when his two penalties sealed a win at Chelsea which confirmed Villa as league champions.