The word 'passion' is defined as strong and barely controllable emotion and there will inevitably be a YouTube highlight reel dedicated to the passion of Manchester United's Lisandro Martinez by the end of the season.
Martinez has bumped his chest with Diogo Dalot, affectionately slapped David de Gea over the head, fist-pumped his own clearances and thrown himself into the away end at Stamford Bridge in just a few months since signing from Ajax. Erik ten Hag said he wanted to sign characters and he's certainly got a personality with Martinez.
Ten Hag was asked about Martinez losing himself in the Stamford Bridge away end after Casemiro's dramatic equaliser and he was smiling when he said: "We are United. And so it's on the pitch and we want to have a good relationship. We want to get a vibe in and work together and I think Licha really express that always in his game. With his [passion] what he's bringing in.
"So every challenge, every duel, he gives everything he has, and I think the fans they love it. Not every player is like that but I think you need some players in your team who express that and I think that also gives a really good connection with fans."
It's difficult to remember a time when supporters have immediately taken to a new signing like they have Martinez. Robin van Persie and Bruno Fernandes made similar first impressions, but Martinez shows such personality on the pitch, which is rare.
The dressing room last season was devoid of confidence and belief and Ten Hag needed to address that mentality. Ten Hag worked with Martinez for three years at Ajax and he knew the centre-back would be the perfect addition to the group.
Martinez has been outstanding on the pitch, first and foremost, as he's made a mockery of those who suggested he couldn't succeed in the Premier League due to his height, but the difference he's made in regard to the mentality of the dressing room can't be stated enough. He trains exactly as he plays and his infectious personality has raised the spirits of everyone within the squad.
There has been a distinct lack of characters at Old Trafford over the last five years and the Argentine, who wears his heart on his sleeve in every match, despite that being an overused cliché, is the player who the club desperately needed.
Martinez is consistent in his beautifully old-school approach and that means his personality is also evident when he represents Argentina and perhaps even more so, considering it's where he was born and feels intrinsically connected with.
That personality was on show again at the end of Argentina's match against Mexico on Saturday night, with the centre-back making sure to revel in the celebrations, shouting in goalscorer Enzo Fernandez's face and losing himself in emotion.
Martinez's defensive teammates had already returned to the halfway line for the restart and he was still celebrating.
Martinez has been an invaluable asset to Ten Hag's dressing room this season and he's now giving Argentina that edge at the World Cup. He is a typical 'South American' player in an era which has encouraged players to show minimal personality.
He's been a breath of fresh air in Manchester and there has been substance to his passion, more importantly. The backline was hopelessly porous last season, but Martinez has developed an excellent understanding with Raphael Varane in defence.
United have conceded five fewer goals this season after the same number of games as last year, but the manner of the defensive performances have been far more convincing, with Ten Hag making the side feel less vulnerable.
Martinez will be the signing of the season at Old Trafford if his next six months are just as good as his first four.