If Sergio Leone had to remake The Good, the Bad & the Ugly using Ligue 1 managers as his cast, the iconic Italian director would no doubt plump for disciplinarian Claude Puel as Lee Van Cleef's "Angel Eyes" while strong-and-silent type Laurent Blanc is tailor made for Clint Eastwood's enigmatic "Blondie".
However, unlike in the legendary spaghetti western, you get the feeling that it is the crafty Belgian who will be the last man standing when the dust settles on the shoot-out for the French title this season as his side go into the final four matches of the campaign top of the table, albeit by a single goal.
Whether or not Gerets brings a first Ligue 1 title to the Stade Vélodrome since 1992, though, the Belgian's legacy at OM could well last as long as that left by compatriot Raymond Goethals when he took the side to two European Cup finals in 1991 and 1993, winning the latter.
When Gerets first walked in the door in September 2007, talk of a first championship win since the chain-smoking Goethals' reign appeared as far-fetched as the idea that Wall Street would cause a worldwide economic meltdown.
Fast forward a year-and-a-half, and one major financial crisis later, Gerets' stock is just about the only one gaining in value.
He led the side from fourth-from-bottom to a third-place finish last season, and they have been title-contenders throughout this campaign. More importantly, up until last week's announcement that he would be quitting the club when his contract ends this summer, Gerets has somehow managed to instil stability in a club that had previously been as quiet and unassuming as Lindsey Lohan and Paris Hilton on a girls' night out.
Gerets' low-profile, no-nonsense demeanour has matched his handling of the side, while club president Pape Diouf - a former agent - has used his ties in that labyrinthine underworld to bring in players who have added something to the squad - not necessarily a phrase that could be applied to Marseille's transfer policy for much of the last decade with the Stade Vélodrome having the arrival and departure rate of an Amsterdam knocking shop, though - unlike the Dutch capital's finest red-light establishments, so I'm told - value for money was a rarity.
Like all coaches in Europe, Gerets' input in transfer policy is limited, but the Belgian made the key decision of this season when he identified his team's need for "a big man up front" after their 3-0 bullying by Nancy back in December.
The answer was to bring in Brandao - a Brazilian who has the hair of a 1980s Lionel Richie and the build of a WWE wrestler - from Shakhtar Donetsk for €6m. After a languid start and comments like, "It's so warm here, I'll soon be able to use my pool," Gerets' judgement looked as wayward as the man at the MCC who said, "That Allen Stanford looks like a man you can trust."
However, in recent games, the pony-tailed 28-year-old has shown the toughness which saw him survive six Ukrainian winters, battering opposition defences to allow his team-mates to make Marseille the most prolific attack in Ligue 1 as well as chipping in with four in his last six league games.
Believe it or not, Gerets' magic has even worked on Boudewijn Zenden, with the former Chelsea, Middlesbrough and Liverpool - spot the odd one out - man used sparingly but effectively.
Perhaps Gerets' most mercurial decision was to bring in the virtually unknown Tyrone Mears from Derby County on a season-long loan, seeing the Jamaican international score an improbable winner against Ajax to clinch a UEFA Cup quarter-final place, as well as performing more than adequately in Ligue 1 as cover for first-choice right-back Laurent Bonnart.
Mears, who hardly distinguished himself at Derby, is just one of a number of squad members who can back up striker Mamadou Niang's recent claim that Gerets has "improved the standard of several players."
Nowhere has that phenomenon been more noticeable than in the latter half of the season where a 12-match unbeaten run has been forged largely on second-half performances. OM have been transformed from also-rans into title contenders in the quarter-hour intermission recently, scoring all but one of their last 21 league goals after a half-time "shampoo and set" from the straight-talking Gerets.
It is that sort of Midas touch that has made Gerets a success, and also means the ego that goes with it was unable to take the public sideswipe levelled at him by club owner Robert Louis-Dreyfus in January.
Bearing in mind the timing of Louis-Dreyfus' outburst - hot on the heels of the pre-Christmas demolition by a very poor Nancy side - it was hard to argue with the man, who has poured more than €200m of his own money into the club, when he warned Gerets and Diouf would "have to draw their own conclusions" from a failure to win the title or - at the very least - qualify for the Champions League this season.
"After the Robert-Louis Dreyfus article I felt under attack. He had forgotten how far we'd come," explained Gerets last week when he confirmed he would be crossing 'RLD' off his Christmas card list. "It's a pity. I think this could have been sorted out in five minutes. I swear on the lives of my children that if I had been offered a contract lasting two years or more before the end of March then I would have signed it."
Gerets' repeated declarations of love for the club and the passion of its supporters suggest he would have stayed, and the amour is clearly mutual. Like Goethals, Gerets has earned massive popular acclaim - a Facebook petition begging him to stay was joined by over 14,000 - and he was given a rousing standing ovation ahead of last weekend's 2-2 draw with Toulouse.
What next, then, for Belgium's favourite export after Stella Artois and Jean-Claude Van Damme?
Rumours of a juicy contract in the football desert that is the desert of Saudi Arabia have been mentioned while the more outlandish speculation has Gerets winding up at Stamford Bridge to replace Guus Hiddink, the man from whom he learned the managerial ropes when he was a player under the current Chelsea boss at PSV Eindhoven - see the link? No, thought not.
Wherever he goes, don't expect it to be Standard Liege. The club owner there is called Robert Louis-Dreyfus.