Harper, who headlines the May event, will be joined by fellow Doncaster-area boxers including Ed 'The Farm Boy' Hardy and former world champion Maxi Hughes as they stage open workouts in a specially installed boxing ring before doing Q&A's and taking photos with Doncaster Rovers fans of all ages.
As well as giveaways and some boxing-related games, the FanZone will also feature official photo backdrops of the kind used at boxing press conferences, giving fans the chance to stage their own staredown photos and show the pros how it's done.
"Tickets for the May 23 event have been flying out and now we're really starting to build the buzz as we count down the weeks to what is going to be one of the biggest boxing events of the year, right here in Doncaster," said GBM promoter Izzy Asif.
"Terri Harper is a hometown heroine, so it's nice to have opportunities like this where the fans can get up close with her to take photos and have a chat. She's defending a major world title on May 23 and we're very much looking forward to hearing Doncaster roar when she enters the ring in front of ten thousand fans and with the eyes of the world on her."
Ed 'The Farm Boy' Hardy - a rising young prospect who starts his working day at 4am on the family hill farm before heading to the boxing club in the evenings - is also a popular local figure, with some locals knowing him as much from the cafe at his farm as for his boxing endeavours.
"We call him the housewife's favourite," laughs Asif. "It seems like a lot of people locally know his face from visits to his family farm, where they've got a popular tea room and farm shop.
"He's a very nice, clean cut young man, everyone is surprised to learn he boxes professionally - but he's a terror in the ring. He's got unbelievable power for his size - real farmer strength - and you'd be amazed how many fellow young boxers seem to have their phones on silent when we're calling them asking them if they'd like to face Hardy!"
GBM: Harper vs Zimmermann takes place Friday, May 23 at the EcoPower Stadium in Doncaster and airs live and exclusively worldwide on DAZN.
Tickets are on sale via the Doncaster Rovers FC website.