Joe Joyce says heavyweight boxing can be like “swimming in treacle” but he never considered retirement after successive losses to Zhilei Zhang.

Joyce, 38, fights fellow Briton Kash Ali on Saturday in Birmingham in his first outing since September.

He says he experienced “dark times” since losing his undefeated record.

“Mentally, it has been tough,” Joyce said. “Getting slagged off on social media with certain people telling me I should retire, you have to be strong.”

The losses to China’s Zhang were the first of Joyce’s previously perfect professional record.

Zhang secured stoppages in both fights, but the September rematch ended in a brutal knockout for Joyce, another first for the English fighter, who says losing is a lonely feeling.

“It did take me a little while to get over the losses because people treat you differently after the fight,” he said.

“I already get out of the arena late after [drug] testing and there’s already people taking apart the ring and everyone has left, but then there’s the extra thing of losing and seeing everyone’s disappointed faces.

“I’m used to winning and people being excited to see me.

“It’s like a fork in the road or maybe a tree has fallen in the road, so I have to either saw it in half and move it in bits or maybe just try and drive through it or maybe take a different route and I guess that’s what I’ve had to do.