Poland could be without Kamil Glik at the World Cup after the defender injured himself within hours of being included in Adam Nawalka's 23-man squad.
The Monaco defender hurt his shoulder while reportedly attempting a bicycle kick in a hybrid game of football-volleyball in training on Monday.
The 30-year-old had already been included in the list of players Nawalka submitted to FIFA and will undergo assessment in Nice on Tuesday.
Stuttgart defender Marcin Kaminski, one of 12 cut from the 35-player preliminary squad, will remain on stand-by until the extent of Glik's injury is known.
While the absence of the former Torino man would come as a major blow, Poland are able to call on star striker Robert Lewandowski for their first World Cup appearance since 2006.