Pressure cooker clash a challenge for hothead Diouf
El Hadji Diouf is not known for his self-control, which makes you wonder - or worry - about how Rangers' new signing is going to react to his first Old Firm clash on Sunday.
With next-to-no-time to settle in following his last-minute loan deal, a man often dubbed the 'most hated man in British football' is about to be catapulted into the most acrimonious fixture on these isles.
And what a reception it promises to be, for Diouf was already persona non grata with Celtic fans after spitting at one of their number when representing Liverpool in a 2003 Uefa Cup clash.
But this constant bedfellow of controversy - his latest incident, Jamie Mackie-gate, seemingly sparking his Blackburn exit (coach Steve Kean never selected him again) - claims to thrive on adversity and, one way or another, he's unlikely to go missing.
"I know people will boo me but I love that. The more you boo me the more power I get," says the Senegalese, who should be flying by the 90th minute in Ibrox given the vitriol that has already started. "I don't want people to love me - I just want them to respect me."
Yes, he did really say that - but respect is not the quality most have for the two-time African Footballer of the Year. After the incident with Mackie (which Diouf denies), QPR boss Neil Warnock described him as 'lower than a sewer rat'.
Diouf was on the end of some rash challenges against Hearts on his Rangers debut: Photo: Reuters
Many would agree and few fans in England will bemoan his departure.
That's because his list of unsavoury misdemeanours is implausibly long and varied, so much so you probably couldn't name them all off the top of your head, but they range from repeated spitting through car crashes and drink-driving to endless verbal spats.
So why the character?
"People don't like me because I'm a bad loser," 'Dioufy', 29, has said before in an attempt at explanation.
In Senegal, greater insight comes from those who credit his behaviour from his childhood in impoverished Saint Louis, a coastal city whose crumbling facades reflect its faded colonial grandeur and harsh existence.
Diouf, they say, was used to having to defend himself on the streets and the mentality is so deeply ingrained that no amount of money nor privilege can exorcise it.
Nor popularity. Despite his infamy, his face still adorns posters representing some of Senegal's biggest businesses and he's more popular than the national president - his decisive and thrilling role in taking Senegal to the 2002 World Cup quarter-finals never to be forgotten.
In fact, when he quit international football in 2007, superstar singer Youssou N'Dour was among those beseeching 'le badboy' to reconsider - which he did (only to retire again after the failure to reach South Africa 2010, although he has since made himself available).
His ability aside, the main reason most Senegalese tolerate Diouf is because he gives a great deal back to society, mainly through charitable donations.
Three years ago, he set up the KONFIDENCE foundation with another Senegalese star - the rapper Akon - with a brief to help hospitals, education, sick children and improve sports facilities so others can profit like he did.
And another charity aimed at boosting the fortunes of Senegalese children through further improvements in education and health is in the pipeline.
"Everybody in Senegal knows he helps a lot of people, which is why he's still so popular," says Dakar-based sports journalist Aliou Goloko. "Diouf has two faces. On the pitch, he has to win and will address any provocation, which some knowing opponents abuse. But off it, he's a very lovely person - and people find that surprising."
Speaking from my own experiences while based in Senegal, it would be remiss to state that Diouf was anything but charming and friendly on the occasions we met.
Few will defend the former Liverpool, Bolton and Blackburn forward but one man who regularly stands by him is Sam Allardyce, whose advice Walter Smith sought before deciding upon a move which has, in the eyes of some, already stained the Rangers boss' character.
Smith's challenge is how to maximise Diouf's undoubted ability and if he listens to Allardyce and other coaches who've got the best out of him - such as Joel Muller (Lens 2001-02) and Bruno Metsu (Senegal) - he'll know that giving him a degree of respect and freedom should reap dividends.
In return, an appreciative Diouf will work hard to repay that faith but Smith must ensure the Senegalese learns to keep his mouth shut, since his lip is often the catalyst for any downfall.
Smith has successfully handled other wayward characters before, e.g. Paul Gascoigne, but he may find Diouf needs only a steer here and there to produce his best.
For the passion to succeed should come from within as with time ticking on his career, the Senegalese only has one club honour to show from a 14-year European odyssey: the 2003 League Cup medal he won with Liverpool.
Although his pace has long gone, the versatile Diouf is still a highly-skilled player who can beat defenders and deliver dangerous crosses - hence, Smith's gamble as he tries to catch league leaders Celtic (Rangers trail by five points with two games in hand).
"I want him to be remembered for his football," says the Rangers coach, who has backed Diouf to handle the flak.
Meanwhile, the Senegalese says he wants to become a Rangers legend and despite his advancing years he certainly can deliver in Scotland.
But will controversy undermine him again - or can one of football's ultimate hotheads handle the pressure-cooker situation of an Old Firm derby?
His flashy feet will surely flourish - his legacy will come from his head.