German tennis star Alexander Zverev is preparing for a High Court fight with a London-based sports management company which began representing him when he was a teenager.
Zverev, 23, has sued Ace Group International and made an “unlawful restraint of trade” claim.
Ace disputes his claim.
Judge Andrew Hochhauser is due to begin considering evidence at a High Court hearing in London on Thursday.
Detail of the case emerged at a pre-trial hearing earlier this year.
A barrister leading the star’s legal team said Zverev, currently ranked seventh in the world, entered into a representation agreement with Ace in 2012, when 15.
Anya Proops QC said he had tried to terminate the relationship, but Ace had denied his “right to do so”.
Nick De Marco QC, who led Ace’s legal team, said Ace argued that the contract was not “in restraint of trade”.