Manny Pacquiao won’t walk away from boxing until he feels he is no longer an elite welterweight.
Thurman is the best fighter Pacquiao has shared a ring with since he was masterfully beaten by Floyd Mayweather in 2015.
Wins over Timothy Bradley and Adrien Broner were impressive, but they are not on the same level.
The loss to Mayweather has been blamed on a shoulder injury and he is desperate for ‘Money’ to return for a rematch.
But it is Pacquiao’s elite credentials that are under examination this weekend in Las Vegas.
Since Mayweather there has been a seventh career defeat to a much-lesser foe in the shape of Jeff Horn, albeit controversial, this is evidence that Pacquiao will fail this latest test.
But he has proved many doubters wrong in the past.
It is how he became a star in the division when he fought Marco Antonio Barrera as an underdog in 2003.
That night the Freddie-Roach trained puncher arrived on the big stage. Now he is back with his long-time trainer.
At 40, those blisteringly-quick hands have slightly slowed and the reactions are not what they once were for the eight-weight world champion. Thurman is a top welterweight and is in the mix with IBF champion Errol Spence Jnr and WBO title holder Terence Crawford as the best in the division.
The American’s below-par performance against Josesito Lopez can be discounted as a fight shaking off ring rust.