Timothy Fosu-Mensah has completed his move to Bayer Leverkusen from Manchester United for £ 1.8 m.
After refusing a new United deal, Ajax, Marseille, and Hertha Berlin were also involved, but Leverkusen, who are third in the Bundesliga table, won the race.
Since making his debut as a substitute in the 3-2 victory over Arsenal in February 2016, Fosu-Mensah has only played 30 times for United.
In the Champions League group game against RB Leipzig in Germany on December 8, what turned out to be his last appearance for the club came as a substitute.
In the January transfer window, Fosu-Mensah may not be the final player to leave Old Trafford, with representatives of Jesse Lingard having talks with Ligue 1 side Nice about a possible loan move.
The 27-year-old started on Saturday with the United FA Cup win over Watford but hasn’t been called for more than a year in a Premier League start XI.
Last month, La Liga club Real Sociedad was confirmed to have held initial talks on a potential midfielder loan contract.
Representatives of Lingard also had talks in the summer with many clubs in England and Europe, but a move did not materialize.