By Keith Idec

Errol Spence Jr. was as surprised as most of us when Kell Brook embraced a two-division move to challenge intimidating middleweight champion Gennady Golovkin.

The undefeated welterweight contender expects Kazakhstan’s Golovkin to knock out Brook when they meet September 10 at O2 Arena in London (HBO). He still respects Brook for accepting a daunting challenge most middleweight title-holders have avoided over the past several months.

“I think everybody is surprised that Kell Brook took that fight,” Spence said during a conference call Wednesday. “He’s moving up to 160 to fight Triple-G, a very hard puncher, a knockout artist. Triple-G been heard to knock out heavyweights in the gym. So for him to move up and take that fight, it takes a lot of guts. I applaud him on it. But I haven’t really gave it too much thought. You know, he was on my mind because he had the IBF [welterweight] belt and was fighting at 147. But right now, he’s not on my mind at all.”

Speculation persists regarding Brook’s plan to relinquish the IBF welterweight title no matter what happens against Golovkin (35-0, 32 KOs). The unbeaten British champion reportedly has outgrown the welterweight division and won’t want to come back down to 147 pounds after a two-month training camp for his middleweight debut.

If the 26-year-old Spence (20-0, 17 KOs), of DeSoto, Texas, defeats 41-year-old contender Leonard Bundu (33-1-2, 12 KOs) in their IBF welterweight elimination match August 21 at Brooklyn’s Ford Amphitheater at Coney Island Boardwalk (NBC; 5 p.m. ET/2 p.m. PT), he’ll become the IBF’s No. 1 challenger for Brook’s title. The 2012 Olympian isn’t sure, however, if a victory over Italy’s Bundu would eventually result in the powerful southpaw boxing Brook (36-0, 25 KOs) or someone else for the IBF belt.

“It’s something I haven’t asked and haven’t gave any thought since I got the Bundu fight,” Spence said. “I can’t look over Bundu. Bundu is an experienced fighter, has been in a lot of fights and has a lot of good tools. So I can’t disrespect Bundu and look over him. I look over him and I end up not looking good, losing or whatever. Then I’m not fighting for the IBF title. So I take one fight at a time. I’ll fight Bundu and not worry about the IBF title. And the IBF is real good at enforcing their rules, so I’m not worried about that at all.”

Three weeks after he battles Bundu, Spence plans to watch the Golovkin-Brook bout with more personal interest than most.

“I think Triple-G will knock him out, but I give Kell Brook a chance,” Spence said. “He’s fighting in the UK, so who knows? If it’s a close fight and it goes the distance, he could get the nod. But if I was to bet on it, I would have Triple-G for a knockout.”

Keith Idec covers boxing for The Record and Herald News, of Woodland Park, N.J., and BoxingScene.com. He can be reached on Twitter @Idecboxing.