The German Football Association will investigate a clash between Stuttgart goalkeeper Jens Lehmann and Borussia Dortmund defender Neven Subotic in their Bundesliga fixture last weekend.
Both players were seen to raise elbows and Lehmann was left with a split lip as the pair jostled prior to a throw-in in the 44th minute of the 1-1 draw.
The players went unpunished during the game, allowing retrospective action to be taken using television evidence.
Lehmann and Subotic are ''under serious suspicion'' of having acted in an unsporting and violent manner, according to a statement from the DFB.
''Lehmann intentionally struck Subotic on the back of his head with his right elbow, to which Subotic reacted and consciously struck Lehmann in his face with his left elbow,'' added the DFB.
Lehmann and Subotic have been asked to provide a written statement explaining their actions.
The DFB's referee panel will then decide what action to take, although they added in their statement the players can expect to be punished if found guilty.