Premier League players are underperforming on the pitch because of worries arising from poker games on the team coach or at hotels before matches, according to new research.

Top footballers are also using online betting sites to conceal their gambling from their partners, the British Sociological Association’s annual conference in Birmingham will be told today.

The revelation comes barely a day after Manchester City defender Martin Demichelis admitted 12 breaches of Football Association rules governing betting on matches.

Graeme Law, of the University of Chester, interviewed 34 current and former professional footballers, including international and Premier League players, as well as those in lower leagues.

Players talked about how worries caused by gambling had impaired performances on the pitch.