The London Evening Standard reports that the highly-rated 20-year-old is out of contract with League Two side Stevenage at the end of the season, and has been spending time with a number of clubs including Manchester United and Watford, but has most recently been training with Spurs.
Johnson was a part of the Tottenham under-23 side that were beaten 4-1 by their Everton counterparts on Monday, but despite that scoreline, the London Evening Standard adds that Spurs felt the trial went well and thus, plan to keep the Northern Ireland under-21 international on their radar.
While Johnson is currently plying his trade in the fourth tier, he has experience of being attached to a team at the highest level, having spent around seven years on West Brom's books before leaving in 2013.
Before this season, Johnson had made 12 appearances for Stevenage but has spent much of this campaign out on loan with non-league side St Albans.
And while it may be a surprise to hear Tottenham plan to keep their eye on Johnson given his recent lack of game-time and the fact that their under-23 side suffered such a heavy defeat in the game that the youngster featured in, it seems that the Spurs hierarchy feel that there may be something there to work with in the future.