Köster Rejoins Swiss Football on Loan

Swiss return for Union Berlin midfielder

Leonie Köster is heading back to familiar territory. The 25-year-old midfielder has sealed a loan switch to YB Frauen from 1. FC Union Berlin, marking her return to Swiss football after a gruelling spell on the sidelines.

Champions League opportunity awaits

The move offers Köster a fast track back to competitive action. YB Frauen face SKN St. Pölten in the second qualifying round of the UEFA Women's Champions League in early August - giving her a shot at meaningful international minutes almost immediately, as reported by Soccerdonna.

Long road back from injury

Köster's path here has been anything but smooth. She joined Union Berlin from FC Basel in January 2025 but managed just two 2. Bundesliga appearances before a February clash with 1. FC Nürnberg ended in an injury requiring surgery. She was sidelined for 325 days before returning in a test match in January 2026. Union extended her contract that same month, though the length remains undisclosed.

This past season brought just one Bundesliga outing and a single Regionalliga Nordost appearance for Union's reserves.

A well-travelled career

Köster's CV is impressive. She started at FC Bayern, racking up 51 matches across three 2. Bundesliga seasons, before spending three years at Eintracht Frankfurt with 30 Bundesliga appearances. Her time at FC Basel from 2023 to early 2025 produced 30 Women's Super League matches, five goals, and eight Swiss Cup outings with two more strikes.

She also represented Germany's youth national teams 24 times, finishing as runner-up with the U17s in 2018 and reaching the U19 final a year later.