Gagnon-Lapare, 21, is a Homegrown player who has been on the Impact roster since 2014. This season, he has made no MLS appearances for Montreal, although he did make 13 appearances this year for the club's USL team, FC Montreal, where he notched one assist. He also made one appearance in the 2016 Amway Canadian Championship for the Impact. Gagnon-Lapare has five caps with the Canadian national team to date.
Rennes, historically a midtable side in France's Ligue 1, currently sit in fifth place in the division. They are known for having one of the best youth academies in France.