If the thick Fife accent was difficult for a Swede to decipher, there was no mistaking the message that came booming through loud and clear.
Mikel Lustig, having just joined Celtic from Rosenborg in January 2012, was given a sharp introduction to the standards expected on captain Scott Brown's watch.
"I remember one of my first training sessions," the 34-year-old defender tells BBC Scotland. "I'd come from Scandinavian football where everyone was quite quiet.
"Scott was yelling and shouting at me - we were in the same team - after we lost possession. I was thinking, 'What the hell? This guy is crazy.'
"But after a while, you know he does it every session and he's doing it for the best of the team. Every day he gives 100% and sets the standard. When people fell below that, of course he's going to say to them."
'The best captain you can ever have'
Brown - who will join Aberdeen this summer - plays his 620th and final game for Celtic on Saturday against his first club Hibernian.
There is no triumphant send-off, with his final season having seen the implosion of the club's domestic dominance. But his contribution over a 14-year spell that garnered 22 trophies marks him out as a Celtic legend and leaves a sizeable void.
For Lustig, Brown is without peer as an inspirational presence. The likes of Sweden colleague Zlatan Ibrahimovic don't even get a look-in.
Lustig's seven-and-a-half years at Celtic brought 12 domestic honours, culminating in the treble treble in May 2019. Managers came and went, but Brown was with him every step of the way, barking, cajoling and organising.
It was an era of success Lustig, now back playing in his homeland with AIK, doubts would have been possible without Brown as the driving force.
"He's absolutely the most inspirational leader I've played with - the best captain you can ever have," says Lustig. "He was really important for me and is still a good friend. Those years when Celtic won everything, he was the most consistent player.
"A lot of games we won were down to Scott's influence. Fans and players of other teams didn't like him but he got a lot of energy from that and thrived on it. There were games we won because of that - it made him better."
Brown's leadership qualities, having captained Celtic for the past 11 years, are well known.
But Lustig believes his ability shouldn't be overlooked, and the Swede describes a unifying dressing-room presence whose snarling on-field persona couldn't be further from the off-field reality.
"His technique is brilliant - he's a really good passer," the former vice-captain says.
"I don't think there was one day at Celtic where I came in and Scott was in a bad mood. He was always upbeat and had such respect from all the players.
"Away from football he's such a humble guy. It's just like when he goes on to the pitch, a switch flicks in his head and he's in game mode.
"He was so important for us players because he is the guy who can speak to the board or the fans.
"It didn't matter if you were Scottish, Scandinavian, French or African, everyone really looked up to him and he helped to bring the squad together.
"It was easy to be a foreign player in the Glasgow derby and other important games because Scott was always showing and telling us what it means to the club."
'He could change a game with one tackle'
Former Scotland manager Craig Levein was there at the very start of Brown's trajectory to the top of Scottish football.
As a boisterous 14-year-old the midfielder was on Cowdenbeath's books when Levein began his management career at Central Park in 1997.
"He played as a winger at times back then. He had good pace, was aggressive - in a positive way - even at that age," says Levein.
"I had a meeting with his mum, who said he wasn't academically-minded. So she was concerned Cowdenbeath didn't have a professional youth team and he'd have to get a part-time job when he just wanted to play football.
"Gordon McDougall, who was chairman at the time, was a big Hibs supporter so he arranged for him to go in there. The rest is history."
Levein and Brown's paths would continually cross again as opponents in the Premiership and colleagues in the international set-up.
When Levein became Scotland manager in 2009, he made Brown the fulcrum of his midfield.
"It's quite a unique thing," he says. "Scott was able to change the atmosphere in a stadium just by smashing somebody.
"The game would be dawdling along and he would come in with an aggressive tackle - nine times out of 10 tough but fair - on one of the opposition's best players and get the punters going.
"That happened with Scotland and numerous times for Celtic. He could sense when the game needed a jolt."
When pitted against Celtic during his tenures at Dundee United and Hearts, Levein found Brown to be a master of gamesmanship with the talent to match.
"It's hard to get players who are capable of winding him up," he adds. "A brilliant contest was him and Steven Naismith - the two of them are as wide as they come.
"You couldn't meet two nicer guys off the pitch, but on it they had some run-ins. And having Steven on the pitch was crucial in trying to help the younger players not get caught up in things because Scott just winds you up, a wee comment as he walks past and all the rest of it.
"It's all gamesmanship to give his team an edge. I always wished he was in my team."