Carlos Tevez a reckless danger on and off the pitch

Last week, a few hours after Juventus's victory over Real Madrid in the first leg of their Champions League semi-final, Carlos Tevez was stopped by traffic police on the French side of the Mont Blanc tunnel, allegedly doing 120kph in a 70kph zone. His driving licence was revoked immediately. The incident seemed typical of the 31-year-old's career: he had just played superbly as his club had produced their best European result in more than a decade and yet he ended the night in trouble with police. There is a wild, reckless streak about Tevez that seems never to go away.

Later in the week Boca Juniors played River Plate in the Copa Libertadores, which inevitably took the mind back to their meeting in the semi-final of that competition in 2004. Boca won the first leg at home 1-0 and trailed 1-0 in the second at El Monumental when, with six minutes remaining, Tevez lashed in what looked like being the winner.

He celebrated by flapping his arms by his sides – a reference to the fact that Boca mock River as “las gallinas”, the chickens, for their repeated failures in big games – and was sent off. River promptly equalised and although Boca subsequently won on penalties, they may not have needed to had Tevez stayed on the pitch. His gesture was funny and provocative, and presumably represented the thoughts of most Boca fans at that moment – “Ha! They’ve messed it up again!” – but it was also incredibly irresponsible.

That captures the essence of Tevez. Nobody has ever doubted his work rate on the pitch. His reputation is of a good trainer, although Paul Scholes hinted last week in his Independent column that Tevez wasn't necessarily the most disciplined during his time at Manchester United. "He looks slim and fit," Scholes wrote. "He seems to have found a bit of peace. He was always a player who needed a reassuring arm around his shoulder."

The Juventus coach, Max Allegri, has given Tevez greater freedom and he has revelled in it – so much so that it now seems likely he will sign a one-year contract extension and so defer his return to Boca until 2016.

Scholes spoke of how Tevez became frustrated in his second season at United, when Dimitar Berbatov often took his place. It is hard to imagine two players whose on-field demeanours are more different. Where the Bulgarian strolls and swaggers, Tevez plays with an inner rage, tearing around the pitch in a blur of obvious effort, something that guarantees his popularity among fans. Which is why it still seems so strange that his most famous moment in a Champions League tie remains – for now – refusing to warm up.

What happened in Munich that night in September 2011 remains baffling. Tevez still insists it was "a misunderstanding" and many of his supporters continue to claim Roberto Mancini was desperate for an excuse to get him out of Manchester City. Tevez went back to Argentina for three months but there were two longer-term consequences. The first was the damage to his reputation, which meant that even though he was available for £10m, he ended up in Serie A. The second was that Alejandro Sabella, who seemed to have decided he was a disruptive presence, was given the perfect excuse not to pick him for the Argentina team.

The two have strangely entwined. Whether there ever can be redemption for Munich is debatable but Tevez now stands one game from his third Champions League final. And his form at the moment is so good that Gerardo Martino, who replaced Sabella as Argentina coach after the 2014 World Cup, has brought Tevez back into the fold and is likely to include him later this week in his squad for the Copa América.

With 20 goals, Tevez is the leading scorer in Serie A this season; he's also made seven assists, leaving him high in the assists chart. He has had the second most shots per game and is 11th in the list of most key passes. Perhaps he would not have stood out so much in a better league but Tevez has also had a decisive influence on the Champions League: only Lionel Messi, Cristiano Ronaldo and Shakhtar Donetsk's Luiz Adriano have scored more goals in the competition this season.

It was Tevez whose influence was decisive in the first leg of the semi-final: it was his cross-cum-shot that Álvaro Morata turned in and it was he who was brought down by Daniel Carvajal before getting up to convert the penalty. He is likely to have a major role to play on Wednesday as well. This may be a Madrid with vulnerabilities but if Juve end up playing on the break they know that in Tevez they have a player who is perfectly suited to the role.

When he has the ball he is direct and technically gifted, adept at bringing others into play. Just as important, however, is what he does without the ball. In the best possible way, Tevez is a nuisance. He will not give a Madrid player a second. He will charge about and hassle and harry. If there is a piece to be picked up he will snaffle it. That, really, is his greatness: he has sublime ability with the attitude of a pitbull. If only he did not have that self-destructive streak.

(Guardian service)