Jurgen Klinsmann says United States attacker Bobby Wood has to play in the upper tier in Germany if the Union Berlin forward wants to break out as a player.

The 23-year-old forward, who has been linked with a switch to Hamburger SV, is currently enjoying his breakthrough season in German football. The Hawaiian has netted 14 goals for second-tier club, having joined the capital side from Erzgebirge Aue last summer.