Stuttgart have completed the transfer of Groningen striker Filip Kostic on a five-year deal.
The cost is thought to be in the region of £5m, with further performance-related add-ons included.
The Serbia Under-21 international started 40 games for the Dutch side last season, scoring 11 goals from a wide position.
Stuttgart, who narrowly avoided relegation last season, have recently appointed Armin Veh, who led the club to Bundesliga success in 2007 as their new manager.