Zenit have signed Wilmar Barrios from Boca Juniors to replace Leandro Paredes following the midfielder's sale to Paris Saint-Germain.
Barrios was a key part of the Boca side that reached the final of last year's Copa Libertadores, but he was sent off in extra time as River Plate triumphed in the second leg of the Superclasico at the Santiago Bernabeu.
The Colombia international has signed a four-and-a-half-year deal with Zenit, who did not release details of the fee paid to Boca.
Barrios, who played three games at last year's World Cup, is the latest player to be prised away from Boca after their Libertadores run.
Lisandro Magallan joined Ajax and his fellow defender Leonardo Balerdi was bought by Borussia Dortmund.