LAS VEGAS – Lennox Lewis wouldn’t predict who would win the Anthony Joshua-Andy Ruiz Jr. rematch.

Lewis did divulge that Joshua will have difficulty withstanding Ruiz’s power once again when they square off Saturday in Diriyah, Saudi Arabia. The retired heavyweight champion realized just how hard Ruiz punches when he called one of Ruiz’s fights for FOX earlier this year.

Lewis recalled recently during a group interview at MGM Grand the thudding sounds he heard when Ruiz repeatedly punched Russian veteran Alexander Dimitrenko. Ruiz defeated Dimitrenko by technical knockout following five one-sided rounds in the bout before Ruiz stopped Joshua in what amounted to the biggest heavyweight championship upset since Hasim Rahman knocked out Lewis 18 years earlier in Brakpan, South Africa.

“Andy Ruiz can punch like a motherf---er,” Lewis said of what he learned while watching Ruiz-Dimitrenko on April 20 in Carson, California. “That guy, I was at ringside, and all I could hear was, ‘Boop! Bop! Boop! Bop!’ I’m like, ‘What the f---?’ Every time he was hitting [Dimitrenko], I can hear these punches. I was like, ‘Whoo!’ ”

The 6-feet-2 Ruiz dropped Joshua four times – twice apiece in the third and seventh rounds – on his way to a seventh-round TKO victory June 1 at Madison Square Garden in New York.

Speculation persists that Ruiz will weigh in lighter Friday than the 268 pounds he was when he stepped on the New York State Athletic Commission’s scale for the first Joshua fight six months ago. Lewis isn’t convinced coming in lighter will benefit Ruiz, though Lewis wouldn’t necessarily consider that an advantage for Joshua, who also is expected to come in less than he weighed for their first fight (247¾ pounds).

“I’m not sure, because talking to his ex-trainer, Freddie [Roach], he’s trained Ruiz and he’s always said, you know, when Ruiz loses weight he’s not as good,” Lewis said. “I don’t know. I say if he loses weight, he’s quicker, but still punches [hard].”

The 30-year-old Joshua (22-1, 21 KOs), of Watford, England, is listed as slightly more than a 2-1 favorite to win back his IBF, IBO, WBA and WBO titles from Ruiz (33-1, 22 KOs), of Imperial, California.

Their immediate rematch will headline DAZN’s stream Saturday in the United States from Diriyah Arena (11 a.m. ET/8 a.m. PT). Joshua-Ruiz II is the main event of a Sky Sports Box Office pay-per-view event in the United Kingdom (5 p.m. GMT; £24.95 in HD).

Keith Idec is a senior writer/columnist for BoxingScene.com. He can be reached on Twitter @Idecboxing.