At the end of the 2013–14 season, Sommer won the league championship with Basel. They also reached the final of the 2013–14 Swiss Cup, but were beaten 2–0 by Zürich after extra time.
Sommer led Basel to league supremacy at the end of the 2013–14 season. The team also reached the 2013–14 Swiss Cup final but were outdone by Zürich after extra time.