A Milan court heard an appeal on Friday from small operator Conto TV, which says the way Serie A satellite TV rights for the next two seasons were sold to Sky Italia was unfair.
If the judge rules in Conto's favour then the 1.149 billion euros contract could be blocked and Italian clubs would suddenly be in serious financial trouble given much of their budget planning is based on TV deals.
However, Conto TV chief executive Marco Crispino was not confident his action would be successful.
"We are small and therefore we will lose," he told reporters.
Bruno Ghirardi, lawyer for the Italian football league, said: "We have not broken any law. Up until today it still hasn't been specified what law we have broken. The truth will emerge. Our behaviour has been fair."
Legal wrangling over the case have been rumbling on through Italy's complicated legal system for months but the Milan judge should have the final say.
If he rules against the league then Italian football could plunge into crisis given there would be only three months before the start of the new season to agree amended rules on the sales of rights and renegotiate a fresh deal.
Sky Italia, which has said it honours its contracts, is a unit of Rupert Murdoch's News Corp.
