A late starter in the game, Gerry was 21 when Terry Neill signed him in November 1975 and he admits to being initially overawed before being taken under the wings of our resident Irish contingent.
"I never played until I was 17," says Gerry, speaking at the studios of Sky Sports, for whom he provides expert analysis on the Spanish Primera Liga.
"All my early days were spent playing gaelic football and hurling, which were tough sports. I often got sent off for fisticuffs and started playing football while I was serving a long suspension!
"I got picked up by Bangor and was sent off in my first game. But I was okay after that and had a lot of attributes, like strength and pace, although I was very raw and needed loads of work on technique.
"Spurs asked me to go for a week's trial and I thought I did okay but I heard nothing for weeks.
"Arsenal were trying to sign me but, out of the blue, Terry came over and signed me on a one-year contract, with a one-year option. It was an opportunity I couldn't turn down.
"I was overawed. I'd never been to London before, so it was like 'Paddy' coming to the big city and being lost. But all the lads were great and there were a lot of Irish boys, like Chris McGrath, Noel Brotherston and, of course, the legendary Pat Jennings.
"Pat was great and went out of his way to make me feel welcome, even though he was a first team star.
"I loved the training and I was in the gym every afternoon, working on my skills with Peter Shreeves alongside the likes of Glenn Hoddle, who could do incredible things with a ball."
At the time, Neill's days were numbered and, though his departure for Arsenal during the summer of 1976 came as no surprise, his legacy provided one of the lowest moments in the Club's history, when Keith Burkinshaw, a popular replacement, was powerless to prevent a slide into the second division in 1976-77.
Gerry had made his debut in an opening day defeat at Ipswich but was ditched after three matches. He returned in February for the final 18 games but says it was a hopeless cause.
"It was a c**p season and we were playing poorly. People kept telling us we were too good to go down but what a load of rubbish that was. You don't want to believe that sort of nonsense.
"We started thinking they were right but you had to earn the right to stay up and we lost too many games, simple as that. The game that actually sent us down was a 5-0 defeat at Manchester City, which was horrendous.
"I remember Peter Barnes chipping the third past Pat and they just ran riot after that. They tore us apart and our confidence was shot. When you're in relegation trouble you are afraid to get the ball and make mistakes.
"With hindsight, though, I reckon what gave us such a bad season was going on a five-week world tour at the end of the 75-76 campaign. We travelled to Canada, USA, Hawaii, Fiji, New Zealand, Australia and India and when I got back I was absolutely knackered. But we only had 10-12 days to recuperate before pre-season began.
"The other thing was it was also a learning curve for Keith. He'd never been a manager and, because he'd been close to us, a few players would try it on a bit with him. We all liked Keith but the lads would sometimes step over the line."
Calmer waters lay ahead and relegation soon became a distant memory as a revitalised squad took the second division by storm. It was a season of mixed personal fortunes for Gerry, who was persuaded to fill in at centre-half on too many occasions for his liking.
However, despite a late hiccup or two, promotion back to the top flight was secured at Southampton on the final day and Gerry proudly remembers a season which contained a fair share of what he liked best - battling.
"In hindsight, going down was a good thing because we started from scratch, came back up and went on from there. It was a fantastic season, although I played a lot of games at centre-half. But I played a great game up front at Stoke in October, when we won 3-1 and I scored twice after filling in for John Duncan.
"It was a good game and they had Dennis Smith at centre-half. He was a hard player but I loved the physical side of it and we really went for it.
"I'd done him once, really badly on the knee, and thought he was finished but he's got up and the next ball that's come in he punched me right in the nuts!
"It was like that for the whole game but I loved a real war like that and he was an honest, tough competitor. I've gone in the bar afterwards, all black and blue, and I'm speaking to Ian Moores, who used to play at Stoke.
"I've gone 'Bloody hell, Mooresey, he don't half put it about'. Ian's replied: 'Funny that, he's just said the same about you!'.
"It was a great season because it was so important to go up, but we nearly lost it three games from the end when we lost 3-2 at home to Sunderland after I made a mistake playing at centre-half. But then we beat Hull and went to Southampton needing a point.
"It was tense, obviously, but they needed a point as well and it was one of those games where nobody really tried to push on because of the fear factor. We got our point and went off to Cornwall for four days to celebrate!"
Spurs were on the up and the arrival of Ossie Ardiles and Ricky Villa soon afterwards further lifted burgeoning spirits as the two World Cup-winning Argentines bore the brunt of Peter Taylor's infamous wit.
"The social side was fantastic. I was a bit of a crooner and did all the singing at parties to keep the lads going. That side of it was great but it was easier then because there wasn't the media coverage and we could get away with things you can't now. I'm working in the media business but it's got too much.
"There were funny moments every game and whenever Peter Taylor and Terry Naylor were in the squad it was hilarious. Peter was so funny and his antics were brilliant. The best was after Ossie and Ricky joined in pre-season. We were staying in chalets of three, so they put them in with Peter. Bad move.
"The next day they've come out for training and we're trying to communicate. I said I was from Belfast. Ricky's gone: 'Belfast?' and swung his arm like he was lobbing a grenade.
"We've started to do some stretching and Pat Weldon, the coach, has gone: 'Come on Ricky, bloody good stretch son'. Ricky's smiled back, like he always did, and gone: 'B******s'.
"Ossie was effin' and blindin' but it was only what Taylor had been teaching them in the chalet. Brilliant!
"Gerry did not feature much during 1978-79 but was back in favour for the following term, when Ardiles provided the best moment of the 1979-80 campaign by scoring the only goal in a dramatic FA Cup third round replay win over Manchester United at Old Trafford.
"That was an incredible night and that match had everything you could ever ask for - Milija Aleksic getting done by Joe Jordan, Glenn going in goal and I can still see Ossie with the ball at his feet before whipping it into the bottom corner.
"But Spurs struggled to score goals and a second consecutive mid-table finish meant, deep down, Gerry knew his days were numbered. Typically, however, he recounts his departure from The Lane with candid good humour.
"Me and Chris Jones had been playing up front but we weren't scoring enough. I always worked hard but was never a 15-20 goals-a-season man. I was a good target man who created a lot of chances for other people and Glenn scored 19 league goals in 79-80 feeding off me.
"They signed Steve Archibald for a million, which meant either me or Jonesey was getting blown out. I said to him: 'Well, that's the partnership broken up, pal'.
"Three days later they've signed Garth Crooks for £650,000 and Chris has gone: 'Well, mate, looks like both of us are out now'.
"The Press gathered and Steve Perryman said they were looking for a quote about us being blown out. I've gone out and the fella's gone: 'Well Gerry, they've just signed Archibald and Crooks, what do you think?'
"I replied that I didn't mind which of the two I played with! Everyone laughed but it was the beginning of the end for me at Spurs."
Gerry joined Watford in November 1980, where he helped the Hornets reach the top flight under Graham Taylor before finishing runners-up to Liverpool on 1982-83. He then moved to Spain, enjoying three good years with Real Mallorca before returning to join Brighton, where he ended his professional career in 1988.
He appeared 63 times for Northern Ireland, playing in two World Cups (1982 and 1986) and scoring 12 goals, the most memorable of which came on a balmy evening in Valencia on June 25, 1982, when his strike earned the Irish a famous 1-0 win over hosts Spain.
After a spell as player-coach at non-league Crawley Town he managed Worthing before joining the Northern Ireland national side as assistant-manager to Bryan Hamilton between 1994 and 1998.
Gerry settled in Brighton where he now lives with second wife Caron and daughters Ashleen and Caitlin. He also has two sons from his previous marriage, Ciaron and Brendan, who currently trains with Barnet.
Nowadays, he enjoys the luxury of watching the world's best strut their stuff as a popular and knowledgeable match summariser for Sky Sports and Eurosport, but he looks back at his time at The Lane with genuine pleasure, especially as he still holds the sprint record around the track.
"Martin Chivers held the record but, after having a bet with Keith Burkinshaw, I beat it with 49 seconds which Roy, the kit-man, still tells the lads about.
"I loved the Spurs fans but I remember we were playing Swindon in a cup replay, when I was having a nightmare. I'd given away the penalty, we were losing 1-0 and they booed when Jonesey was taken off instead of me. But I scored a couple of crackers, we won 2-1 and I got a standing ovation!"
By Neale Harvey - Spurs Monthly
Gerry Armstrong is unlikely to feature in many fans' lists of all-time favourites but over five seasons of contrasting fortunes at The Lane the rumbustious young Ulsterman offered a potent mix of raw power, aggression and good humour that endeared him to supporters and colleagues alike.