Britain's exit from the European Union could have a negative impact on speedway, according to Leicester Lions owner David Hemsley.
Riders often race for multiple teams around Europe and Hemsley fears their movement could be limited in future.
"The reality is that at the moment, British speedway simply can't produce enough local British talent," he said.
"It will be a significant challenge to the sport. It's something I hope, one way or another, might get headed off."
Four members of the Elite League side's seven-member team are from EU countries, with Australian Aaron Summers their only rider from elsewhere.
"We've employed Australians, New Zealanders, Americans in the past so we've had to go through the process [of applying for the right to work in the UK] with various riders," Hemsley told BBC Radio Leicester.
"The thought of having to do that for the vast majority of the team fills me with horror. It is very time consuming, it's unwieldy and you feel like your own destiny is out of your control."
In football and other team sports, players with an EU passport are currently free to play in the UK, while those from outside must meet Home Office criteria.
"I hope the UK Border Agency will be used to a massive increase in workload because I am sure that's what they are going to get," Hemsley continued.
"One thing football doesn't do is that their footballers aren't playing for Inter Milan and Barcelona as well as Leicester City which our guys are."
'It's going to be a massive issue'
Lions captain Nicolai Klindt currently rides for Scunthorpe Scorpions as well as Polish side Atlas Wroclaw, Swedish side Elit Vetlanda and Outrup of his native Denmark.
"I was a bit scared about it when I first heard about it because with the visas and the work permit, even though I'm only from Denmark, I'm going to get all that now," he said.
"What I've heard is that it's going to take at least two years before everything is sorted and in that case I could get a British passport because I've lived over here for that long.
"Personally it's not going to be a problem, but for other clubs just look at Swindon, they've got five Australians and they've got to sort out five visas and if that's the case for every single club then it's going to be a massive issue."