Roman Neustadter's spot in Russia's Euro 2016 squad can be locked in after the Schalke midfielder gained citizenship on Wednesday.
Neustadter was included in Leonid Slutsky's 23-man party for the tournament in France, having committed his international future to Russia despite earning two Germany caps in 2012 and 2013.
Slutsky was forced into a change of his initial squad when an ankle injury forced Alan Dzagoev out of the tournament, but any concerns over Neustadter's status were quelled when his documents were processed this week.
Able to play in midfield or the heart of defence, Neustadter will add a versatile presence in Russia's squad.
Slutsky said on Tuesday: "I think it's not a secret that Roman can play a central defender or a midfielder.
"I didn't plan to invent any new position for him. We have two weeks to decide at which of the mentioned positions he will be more useful for the team."