FC Union Berlin will no longer be able to rely on the services of Frederik Rønnow in the remaining matches of the 2025-26 season.

The Köpenick club confirmed this evening, 28 April, that the goalkeeper suffered a muscle injury in their 3-1 loss to RB Leipzig last Friday.

After taking a goal-kick in the 29th-minute, the Danish shot-stopper instantly gripped his calf, indicating to the bench that something was off.

Back-up goalkeeper Carl Klaus replaced him two minutes later, and in doing so made his first Bundesliga appearance for FC Union.

The news comes at an awkward time for the club, who are currently just six points clear of FC St. Pauli in the relegation play-off spot.

So far this season, the 33-year-old has helped Union Berlin keep 5 clean sheets in 30 topflight games, while producing 78 saves in that time.

As a result, Klaus looks set to retain his spot between the posts for their last three games against 1.FC Köln, Mainz 05 and FC Augsburg.