Fernandes made his Stade Rennais debut in the opening game of the season against Lyon, coming on as a 63rd minutes substitute, in a 2–0 loss. Since joining the club, he quickly established himself in the first team, playing in the defensive midfield position. This last until Fernandes suffered a hamstring injury that saw him sidelined for a month. It wasn't until on 10 January 2015 when he returned to the first team, starting the whole game, in a 1–1 draw against Evian. Following this, Fernandes continued to regain his first team place for the rest of the 2014–15 season. In his first season at Stade Rennais, he went on to make thirty–six appearances in all competitions.