Mark-paul gosselaar shirtless

A lot of people remember Mark-Paul Gosselaar from his childhood role as Saved By The Bell 's wisecracker Zack Morris.

Well, things have changed - the actor has come from high school clown to Hollywood hunk, and he has shown off his super buff physique for a VERY steamy new photoshoot.

The 42-year-old bearded star had stripped off completely naked for some seriously sexy black and white snaps, all in the name of promoting his new baseball themed TV show Pitch.

Job done.

The pictures show Gosselaar - who plays fictional San Diego Padres sportsman Mike Lawson - in the nude save for a pair of shin pads, baseball and helmet in hand.

It comes from Thursday's episode, in which the team strip off to support teammate Ginny Baker - played by Kylie Bunbury - after her naked photos are leaked by a hacker.

Saved By The Bell fans can dine at The Max pop-up replica created in 20 days

It's not been easy to get into such amazing shape though, with Gosselaar admitting he's been working out for a long time.

"We didn't put in extra work the day before. We put i extra work months before," he revealed to Entertainment Weekly.

"Production gave us a heads-up that this was a storyline because they know how important it is for us to get into shape and to look the part."

Meanwhile, his ex co-star Dustin Dimond , who played Screech in Saved By The Ball, has publicly apologised to his former castmates.

The 39-year-old hit headlines for all the wrong reasons over the past decade, including being jailed for carrying a concealed weapon and disorderly conduct .

“Oddly enough, it’s doing interviews like this and getting the word out there. This is my best weapon for repairing the damage that was caused by things that were done by people who took advantage of me and the situation I was in at the time," he told Dr. Mehmet Oz on today’s The Dr. Oz Show .

"I will say, guys, I think you're fantastic, working with you has been just one of the icons of my life."