Suker, who maintains close ties to Croatian football and follows Modric's career closely, made the comments during an interview with La Tribu de Radio MARCA.
Asked about the next steps in Modric's career, the former striker offered a striking response.
"Now they asked me where he's going to continue, either in AC Milan or in Madrid... I think something is going to happen with Real Madrid."
Pushed on whether he believed Modric would return to the club he left last year, Suker was direct in his answer.
"He's definitely going to come back, but I don't know in what way... Let's wait for the World Cup to pass and see what happens."
Suker's comments leave open multiple interpretations of what role Modric might play at Real Madrid in the future, though the former international declined to offer further detail on the nature of any return.
Asked directly whether that return would come as a player or in a sporting or technical capacity within the club, Suker chose to stay quiet.
"I can't say more, I can't say more, my friend. Leave it a little in the air, you can't say everything."
He nonetheless reinforced his original message with another pointed remark.
"He's definitely going to do something with Real Madrid, I can assure you of that."
Suker also paid tribute to Modric, describing him as an example both on and off the pitch.
"He's one of the best in the world and, of course, the best in Croatia."
Modric, 39, left Real Madrid last year after over a decade at the club, during which he won numerous Champions League and La Liga titles and established himself as one of the finest midfielders of his generation.
He continues to captain Croatia at this summer's World Cup, with Suker's comments adding fresh intrigue to speculation over his next move once the tournament concludes.
Suker's own connections within Croatian football, and his closeness to Modric's circle, have lent extra weight to suggestions that a return to Madrid in some capacity remains a live possibility.
For now, both men appear content to let the World Cup play out before any decision on Modric's next step becomes clearer, with Suker's intervention likely to fuel further speculation in the meantime, particularly given his standing as one of the most respected voices in Croatian football.