Club Brugge confirmed the midfielder’s absence after leaving him out of their 22-man squad announced on the club’s official website.
The 25-year-old has been linked with a move away from the Belgian champions this summer, with his current contract having just one year remaining.
Onyedika is reportedly close to joining Bundesliga side Eintracht Frankfurt after agreeing personal terms with the German club.
Frankfurt are now understood to be in advanced negotiations with Club Brugge over a deal worth around €10 million for the Nigeria international.
The defensive midfielder played a key role in Club Brugge’s Belgian Pro League title triumph last season, claiming his second league crown since joining the club.
He has also won the Belgian Cup and Belgian Super Cup once each.