He could be one to revive inconsistent the French Ligue 1 side's fortunes, in France and Europe, and save his manager's job.
Paris falls in love with bankable Pastore
It is little wonder Paris Saint-Germain have taken no time to embrace Javier Pastore as a new hero in the French capital. His record, after five games for the club, stands at four assists and one goal.
And while PSG's performances have hardly been stellar, Pastore's contributions have lifted the team into joint third in Ligue 1, two points off the pacesetting Montpellier.
PSG start their Europa League campaign on Thursday night against the Austrian side SV Salzburg and the pressure on Leonardo, the sports director, and Antoine Kombouare, the coach, has already eased after the opening-day home defeat to Lorient. Kombouare was given two games to save his job last month - against Valenciennes and Toulouse - and PSG won both.
Kombouare was part of the successful PSG side of the 1990s that won one league title, two French Cups, one League Cup and reached five successive European competition semi-finals.
He is best known for scoring PSG's most famous goal, a dramatic late strike in the 4-1 win over Real Madrid in the 1993 Uefa Cup quarter-final and perhaps best summed up by his reaction to it.
When congratulated by Michel Denisot, the PSG president, after the game, Kombouare moaned that he had not started. "I said, 'Leave it out, I can't accept that, I just don't understand why I'm not playing regularly'. There are two ways to react: either give up, or prove the manager was wrong, and when I scored that header, I was telling Artur Jorge [the coach] to stick it where the sun don't shine."
His attitude seems to be the same towards Qatari Sports Investments, the club's new owners. "I know how it works round here, if I win games I stay and if I don't, I leave," he said reminding reporters that he was at PSG when Canal Plus, the then-owners brought in new players such as George Weah, David Ginola, Rai and Leonardo, the very same man in charge today.
Kombouare has done a good job steadying a rocky ship in Paris since he was appointed in 2009, although a repeat of last season's fourth finish and a cup final place is unlikely to be tolerated this time around.
There were reports that Leonardo met with Carlo Ancelotti, the former Chelsea manager, to discuss the possibility of him becoming the coach (the Italian was said to be unconvinced by the project, and preferred to stay in London) and while recent results give Kombouare some breathing room, the feeling remains that he is only a few bad results away from losing his job.
Leonardo can also feel relieved: it was he who wanted Pastore, a 22 year old with no trophies and only a fledgling international career with Argentina to his name.
Loved at PSG, despite only playing for one year there, Leonardo spent the last two seasons coaching AC Milan and Inter Milan, without success. His role at PSG, to oversee recruitment, was helped by Qatari Sports Investments spending €90m (Dh451m) on nine new players, a French league record €42m of which went on Pastore.
"Leonardo has not done much in football as a coach. He's an opportunist who happened to meet the guys who own PSG, and I'm surprised they have given him all this power," said Vahid Halilhodzic, the former PSG manager, who added that Pastore was worth "no more than €12m".
Try telling that to the PSG fans now. "Pastore is magic" ran Tuesday's headline in Le Parisien, while L'Equipe wrote, "Paris has a new star". Elie Baup, the former title-winning coach turned pundit, has compared him to Michel Platini and Zinedine Zidane, while the figures tell their own story.
PSG average 2.6 goals per game when Pastore is playing and without him, 0.5 goals. More importantly, his presence appears to bring the best out of his teammates, as they strive to reach his level.
"With his technical ease, tactical vision and strategic intelligence, he elevates the team beyond itself," Bruno Roger-Petit, the columnist, wrote.
"The goal is to be champions in France, and win competitions in Europe," Pastore said after scoring the match winner in the weekend victory over Brest. "Italy is more technical than here, but I feel comfortable on the pitch, even if I am far from my best level."
After losing an experienced spine of Gregory Coupet, Claude Makelele and Ludovic Giuly this summer, PSG's other problem, exposed in that loss to Lorient, was a lack of leadership.
The deadline day arrival of Diego Lugano, the Copa America-winning Uruguay captain, helped solve that problem, even if he will take the place of Milan Bisavec, one of the few new faces wanted by Kombouare, and not Leonardo.
Makelele was also this week confirmed in a new role as "club consultant", though quite how he will earn his reported €90,000 monthly salary remains vague.
The pattern of PSG's season is already taking shape: every defeat increases pressure on Kombouare, every victory serves as vindication for the money spent.
At the moment, the triumphs are coming more often, and expectations are high that PSG can win their first league title since 1994.
"They have to win it, with all that money they've spent," Rudi Garcia, the coach of the reigning champions Lille, said.
Leonardo has, in public at least, claimed realistic targets are the Ligue 1 title in 2013, and a tilt at the Champions League by 2015.
Behind the scenes, those dates have already been adjusted. The European adventure starts tonight, and with Pastore promising his best is yet to come, it will be a fascinating journey. "Paris is a great club and it deserves to be at the top," Pastore said.