Celtic have completed the signing of midfielder Mika Baur from German club Paderborn, bringing their summer transfer window to four new arrivals with an initial four-year contract — plus an option for a fifth.

The 22-year-old's move is structured at around £6.8m in total, with an initial fee of approximately £4.5m and up to £2.3m in performance-related add-ons. A significant portion of those bonuses are tied to Celtic qualifying for the UEFA Champions League league phase — a structure consistent with deals agreed for summer signings Camilo Duran, Kasper Høgh, and Haissem Hassan.

A standout season in Germany

Baur arrives on the back of an impressive campaign with Paderborn, in which he registered four goals and five assists across 33 league appearances. He was a central figure as Paderborn secured promotion from the second division of German football to the Bundesliga, and was rewarded with the club's player of the year award.

Background and Champions League eligibility

The midfielder came through the youth academy at Freiburg before making the move to Paderborn in 2024. He has represented Germany at under-21 level and is expected to be registered in Celtic's squad ahead of their UEFA Champions League play-off tie against LASK Linz next week.