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Borussia Dortmund was the German club where Mikel Merino played. The Spanish midfielder joined the Bundesliga side in 2016 from Osasuna, spending two seasons with the club before moving to Newcastle United in 2018. During his time at Dortmund, Merino made 53 appearances and scored 3 goals, helping the team win the DFB-Pokal in 2017.