World Cup 2018: Poland star Kamil Glik a doubt for tournament after injuring himself trying bicycle kick in training

The Monaco centre-back has injured his shoulder during a pre-World Cup coaching session

Glik was taken to hospital for tests on his shoulder

One of Poland's key players, defender Kamil Glik, could miss the World Cup after injuring himself attempting a bicycle kick in training.

The robust Monaco centre-back was supposed to be the rock on which Adam Nawalka's Polish side were built at Russia 2018, but a cruel twist of fate may yet rob him of the chance to play at the World Cup.

Glik was taken to hospital where a number of tests were carried out on his shoulder. With such a lack of clarity over his situation and with the squad submission deadline on Monday, Nawalka included Glik in his squad but now faces a race against time to be fit for Poland's opener against Senegal on June 19.

The Monaco defender's World Cup is now in doubt (Getty Images)

The 30-year-old defender signed for Monaco two summers ago after impressing during a five-year stint in Serie A with Torino.

Glik also spent a season with Real Madrid earlier in his career and is one of the most-capped internationals in Poland's World Cup squad.