The former Nantes keeper spent the second half of this season on loan at Wigan.
Reports suggest Sporting Lisbon want around £675.000 for the 26-year-old.
“Wigan are negotiating with Sporting and I don’t believe there will be a problem reaching a deal,” said Stojkovic.
“My desire is to stay in the Premier League, but this will only become official after the World Cup.
“I spent six months with Wigan and I think their manager (Martinez) is interested in me.
“This is good news because English football has really impacted on me. It’s really incredible.
“I knew from my first day at Wigan that I’d do a job for the club.”