Arsenal and Manchester United are said to be among the teams chasing after Rennes star Dsir Dou.
The club were not able to reach European football for next season, which will lead to the youngster's departure.
Rennes manager Julien Stephan admitted as much over the weekend, telling reporters: We know today's market, notably for the very young players. He will decide through his personal ambition.
"I'm not naive. We're glad to have developed him during the second part of the season. He's at risk of leaving without a single full season here, that's a shame."
Ouest-France reports that Arsenal and United are both ready to put in summer bids.
Rennes want a fee that will eclipse the club-record 66 million Manchester City paid for Jeremy Doku.