He made his debut for the club, where he started as a right-back, as Guingamp lost 2–0 to Paris Saint-Germain, in the Trophée des Champions. He made his league debut in the opening game of the season, in a 2–0 loss against Saint-Étienne. At the start of the season, he suffered twice a knee injury. Jacobsen then scored first Guingamp goal on 7 December 2014, in a 3–2 win over Reims. In his first season at Guingamp, he made 25 appearances and scored one goal.