Leon Balogun became the club's first signing of the 2018 transfer window after signing a two-year deal in May.
He arrived after spending three years with Bundesliga side FSV Mainz 05, and also had spells with Hannover and Werder Bremen during his time in Germany.
The defender is a Nigeria international, eligible through his father and played in five of Nigeria’s six qualifying games for Russia 2018, helping them to two clean sheets in the process.
The 30-year-old featured in all three of Nigeria's games at the FIFA World Cup and was one of three Albion players at the tournament, alongside Maty Ryan and Jose Izquierdo, who represented Australia and Colombia respectively.
Balogun made his Albion debut against Manchester United, after coming off the bench to replace Lewis Dunk in the 3-2 victory at the Amex.
Internationally, he went on to represent Nigeria at the African Cup of Nations in June 2019.