Jose Luis Castillo is a desperate man. Not only that, he's a desperate Mexican - and it's not wise to wage war against desperate Mexicans.
Which is why you have to hope Ricky Hatton's pre-fight talk is just that, or the Hitman's American dream could turn nasty on the Vegas strip in the early hours of Sunday morning.
"I like to suffer," says Castillo, a phrase that may well be hammered into his tombstone one day.
His first clash with the late Diego Corrales in 2005 was one of the most brutal ever, Castillo finally caving in after almost 10 rounds of heart-rending savagery.
The 33-year-old native of Empalme has been the distance twice with Floyd Mayweather (lost both) and twice with American lightweight great Steve Johnston (won one, drew one).
I'm bang on, I've got the same excitement and motivation as before the Tszyu fight
And he was once chief sparring partner for his legendary compatriot Julio Cesar Chavez, the very model of the ultra-macho, all-action Mexican boxer.
At no point in his 63-bout career has Castillo taken a backward step and he's never been down - yet his eagerly-anticipated match-up with Manchester's Hatton sees him desperate to rescue a tarnished career.
He struggled in his last fight against unheralded Cameroonian Herman Ngoudjo and failed to make weight for his rematch with Corrales (which he won with a fourth-round knockout) and again for the decider, which was promptly scrapped.
That second indiscretion cost him his £450,000 purse, training expenses and a £125,000 fine.
Add to all that the recent death of his brother Cesar from a brain aneurysm and you have the ingredients of a frantic fighter, and one needing a big win to stay relevant.
"It's a chance for me to get back to where I was," says Castillo, a former two-time lightweight world champion. "It will be a war, I just know it.
Castillo (left) lost one of the great fights against Diego Corrales in 2005
"The experience I have, the wins I have against great fighters, are my major advantages. Hatton will never have seen anything like me.
"He is used to slow, cumbersome fighters, but I have real hand-speed and that will cut him down."
The 28-year-old Hatton often talks of toe-to-toe battles in the build-up to fights, but in reality he is far cuter than that.
Against Kostya Tszyu in 2005, Hatton's triumph had more to do with roughhouse tactics and clever inside fighting than crisply-landed blows.
Like Castillo, Hatton has points to prove following two lacklustre displays in his last two fights.
In winning the WBA welterweight crown, Hatton was lucky to sneak a decision against Luis Collazo, and he tired badly down the stretch when reclaiming his IBF light welterweight crown from Juan Urango in January.
A barnstorming display will confound those who believed his best days were behind him and help secure a new three-fight deal with his US paymasters HBO.
It might also pave the way for a dream encounter with Mayweather, who few believe will stay retired for long.
"The achievements have been a little better than the performances in my last two fights," concedes Hatton, who is unbeaten in 42 professional bouts.
"But there have been reasons. Against Collazo, I was fighting in a division I didn't want to be in [a clash with Juan Lazcano at 140lb fell through after Lazcano got injured].
"Against Urango, the hotel air conditioning brought out a head cold in the week of the fight and that affected me in the last four or five rounds.
"I was fighting a couple of awkward southpaws and I was maybe a little complacent without even realising it.
"This is more up my street, someone who is going to stand in front of me. I'm bang on, I've got the same excitement and motivation as before the Tszyu fight.
Hatton says it has been his best training camp ever
"I've been walking around snarling for the last two weeks and I've not had that for the last two fights. On Saturday night, Castillo is going to realise I'm the real deal."
While Hatton maintains he has never had a better training camp, the news filtering out of Castillo's gym is that he is also looking razor sharp.
One thing is certain - it won't be the same Castillo on Sunday morning as the one that stumbled through his last fight.
"Someone like Castillo can be a bit flat when they are given a 15-bout fighter like Ngoudjo, and it was his first fight at light welter," says Hatton.
"But he knows a win against me leads to so many big-money match-ups and he knows if he loses his stock goes down. I expect him to be training harder than he's ever trained."
If Hatton can keep his head while thousands of his fans in the Thomas & Mack Center are losing theirs, rough Castillo up, hold and frustrate, he should complete another famous win.
Lose control and get caught up in another Castillo classic and he could find himself staring down the barrel of a bloody points defeat.
Coverage gets underway at 0300 BST on this website and BBC Radio Five Live with the fight starting at around 0315 BST - it could be a classic.