Japan has been easily beaten 3-0 by European nation Serbia in an international friendly in Saitama.

A Blue Samurai side made up of local players only were disappointed by a second-string Serbia outfit, leaving coach Takeshi Oakada with plenty of questions to answer.

"A match at a time like this is difficult for the players, and we also had some injuries," Okada said according to the Japan Times.

"But they are representing Japan whatever kind of game it is. The team needs to dig in and try to get the win especially when we are losing, and I think we were lacking in spirit tonight.

"I wasn't able to take away many positives from tonight, but I did find out some things about the players. When our key men are missing we really need to find some way to work it out."

Two first-half goals from Vojvodina striker Dragan Mrda and a free-kick from Partizan Belgrade winger Nemanja Tomic did the damage for Serbia.