Manchester-born Watson spent time at the Leicester academy a few seasons ago before accepting an offer to join the Scotland sevens squad. That, in turn, led to an elite development contract with Edinburgh, but he made only sporadic appearances for the capital side before he was officially upgraded to full-time status a few months ago.
Clearly, coach Alan Solomons had seen something he liked in the squat form of Watson, and on Saturday the player let the rest of us in on the secret with a performance of tireless efficiency and devil that earned him a man-of-the-match award and came achingly close to earning his side a famous victory.
The win was snatched from Edinburgh's grasp in the final minute when a collapsed scrum allowed replacement scrum-half David Mele to slot the winning points for the Tigers, overhauling a lead Edinburgh had deservedly taken with a penalty by Tom Heathcote six minutes earlier.
Afterwards, Solomons reported himself satisfied that the Edinburgh players were angry at the outcome of a match that was, fundamentally, simply a pre-season warm-up, an attitude that seemed markedly different to the mood that prevailed last season when even hefty defeats sometimes seemed to provoke little more than shrugs of indifference.
Watson reflected his coach's outlook, saying it was "gutting" for Edinburgh to lose as they did, but he stressed that there were many positives to be taken from a contest in which the Scottish side matched their English opponents in terms of physicality, their abrasive efforts in contact almost unrecognisably better than what they were doing a few months ago.
"It gives us a huge boost," said Watson of the overall performance. "You do all the fitness in pre-season but you never really know how fit you are until you get some game time. But we have Johan Pretorius as our new fitness and conditioning coach and I think it showed. Our fitness out there was really good today.
"If we can be really physical it puts the other team on the back foot, makes our carrying stronger and helps us get quick ball."
"You could see last year that we were getting better as a team in every game and turning into a really physical, abrasive team. I think that showed today, apart from the first 10 minutes when we gave Leicester too much respect. After that we got stuck into them and I think they were a bit shocked by how physical we were. Everyone could see that our physicality really showed."
The suggestion that Edinburgh improved in every game last season was probably overegging the pudding a bit, but there is no question that they look to be in far better shape than they were a year ago.
The signings in the starting line-up - Nick McLennan, Chris Dean, Rory Sutherland, Fraser McKenzie and John Andress - all put in impressive shifts, while Greig Tonks and Tom Heathcote matched each other so well in the playmaking duties that the contest between the two fly-halves could become the most intriguing theme of Edinburgh's season.
"For the first five or 10 minutes we maybe did respect Leicester too much," said Watson of an opening period in which the Tigers moved ahead with a try by Samoan prop Logovi'i Mulipola. "But they are one of the best teams in England and have been for the last 20 years.
"So maybe we respected them too much and maybe they underestimated us. But as the game went on we showed how good we can be and hopefully we can do that throughout the season."
For Edinburgh, Roddy Grant scored a try just before half-time, powering over from a lineout while playing in the unfamiliar No.8 position.
n Heriot's took the inaugural BT Scottish Rugby Charity Shield when they beat Melrose 36-28 in the second match of Saturday's double-header at the Greenyards.
The Goldenacre side had to come from behind, but they lifted the trophy after tries from Jack Turley, Struan Cessford, Cammy Ferguson and Russell Nimmo, along with a penalty try.