Manny Pacquiao (left) and Brandon Rios pose at a news conference ahead of their Nov. 24 fight that took place in Macau, China/Photo by Associated Press

Brandon Rios of Oxnard has lost his past two fights, and that’s enough to ruin anyone’s groove. It almost doesn’t matter that the two losses came to a good fighter in Mike Alvarado and a Hall of Fame fighter like Manny Pacquiao. Bottom line is, Rios can ill-afford a third consecutive defeat when he takes on Diego Gabriel Chaves of Argentina in the welterweight main event Aug. 2 at The Cosmopolitan in Las Vegas (on HBO).

He knows that.

“It’s do or die for me and I will do what I have to do to win this fight,” said Rios, 28, and a former lightweight world champion.

After losing handily to Pacquiao by eight, 10 and 12 points on the scorecards, Rios might have taken on an easier opponent than Chaves (23-1, 19 KOs), who took tough Keith Thurman to 10 rounds before being stopped by Thurman in his only loss last July 27 in San Antonio.

Rios wanted noting resembling a patsy, though.

“I know I could have fought an easier opponent, but I want to show everyone what I am still capable of doing against a top level guy," he said.

Rios is 31-2-1 with 23 knockouts.

Chaves, 28, is ranked as high as the No. 6 welterweight by one governing body. Rios is unranked.