Joe Joyce knew Zhilei Zhang had a lot of experience and gave undefeated Filip Hrgovic everything that the Croatian contender could handle in Zhang’s previous fight.

The big British heavyweight still admittedly misjudged what his fellow Olympic silver medalist could do before their April 15 fight at Copper Box Arena in London. The 6-foot-6, 278-pound Zhang’s speed especially surprised Joyce, who had difficulty dealing with the huge Chinese southpaw’s straight left hand throughout a bout Joyce lost by sixth-round technical knockout due to severe swelling surrounding his right eye.

“I thought I would eventually get to him and tire him and then knock him out,” Joyce told BoxingScene.com. “But I didn’t realize how accurate and fast he was. I underestimated his speed and his accuracy. He’s quite a shrewd character who doesn’t let on too much, but he’s a good fighter and it was a big risk fighting him.”

It was too much of a risk as it turned out for London’s Joyce, who lost the WBO interim title to Zhang and his spot as that sanctioning organization’s mandatory challenger for one of Oleksandr Usyk’s championships. Joyce, 38, exercised his contractual right to an immediate rematch, which is scheduled for Saturday night at OVO Arena Wembley in London.

The 6-foot-6, 256-pound Joyce (15-1, 14 KOs) took a different approach to his recently completed training camp in Las Vegas to better prepare himself for this second shot at the 40-year-old Zhang (25-1-1, 20 KOs), who is slightly favored to beat Joyce again. Most importantly, Joyce, whose lack of head movement has caused problems for him at times, has tried to improve his defense.

“Obviously, I’ve been working on that,” Joyce said. “And I’ve spent a lot more time in the ring with southpaws because it is a tricky style. It’s different because the lead foot is right next to their lead foot and, you know, there’s completely different tactics than I’m used to.

“And Zhang is very experienced. He’s been at a high level in the amateurs. And also, the fight he had before against Filip Hrgovic kinda set him up nicely for a fight against me, which is quite similar. So, he’s had a lot more practice. And now I’ve had more practice and I’ll be in better form.”

The Zhang-Joyce rematch will headline a TNT Sports broadcast in the United Kingdom and Ireland, which is scheduled to begin at 7 p.m. BST. ESPN+ will stream their second clash in the United States, where undercard coverage is set to start at 2 p.m. EDT and 11 a.m. PDT.

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