There have been recent reports and claims of non-selection due to reasons other than football or disciplinary measures - something of great concern to the PFA.

"A professional footballer has a legal right to work which is implied into his contract of employment and forms a fundamental part of it," said PFA CEO Brendan Schwab

"To satisfy this legal obligation, clubs must act in good faith to their players and consider them for selection on merit.

"The PFA's legal advice is that a club fundamentally breaches a player's contract if it refuses to select a player other than on merit, which is confined to performance, fitness and conduct."

Speaking to the PFA's website, Schwab said the union is particularly concerned by clubs that refuse to select a player who: in the last 6 months of his contract, has exercised his right under FIFA and FFA regulations to sign a contract with another club to take effect when his current contract has expired; or if selected, will meet an appearance quota in his contract that would trigger a contract extension such as for another year.

Schwab also said that the PFA's concerns were not confined to the legal rights of the player, but extended to the professional ethos of the A-League and, indeed, the integrity of the competition.

"The suggestion that a professional footballer ceases to give his best upon signing a future contract with another club is ridiculous," Schwab said.

"Only last season, PFA President Simon Colosimo won the Marston Medal in helping Sydney FC to the Premiership whilst having signed to play for Melbourne Heart in 2010/11.

"This is a regular occurrence in the world of professional football."