Sale Sharks signed Denny Solomona after he was “fired” by Castleford, according to the Premiership rugby union club’s director of rugby Steve Diamond.
Diamond has previously said the winger, 23, “resigned” from rugby league.
Rugby league club Castleford say they have been instructed by their legal representatives not to comment.
“It’s in the hands of the legal people, but I don’t see any problems at this moment,” Diamond told BBC North West Tonight.
“I’m confident that we made a substantial offer and it was knocked back.
“For various reasons Denny became available through being fired from Castleford and once he’d been fired we got in touch and signed a contract.”
A sports lawyer has said the legal battle over the player could have an impact on both rugby codes in a way the Bosman ruling affected football.
The case explained
Despite having two years remaining on his contract with Super League club Castleford Tigers, Solomona retired from rugby league and subsequently crossed rugby codes to join Sale on a three-year deal – making his debut in Sunday’s European Champions Cup defeat by Saracens.
Tigers are suing for damages against Solomona for breach of contract and for damages, including exemplary damages, against Sale Sharks and agent Andy Clark for “inducing” the player to breach his contract.
Diamond, who has insisted that the wrangling over Solomona’s contract is not a ‘rugby league versus rugby union’ case, said an offer to sign the player from Castleford was rejected.
Castleford had continually said that they would not welcome an approach for the player.
The Tigers are taking the case to the High Court in Leeds, having appointed London barrister Nick Randall QC and Leeds-based sports lawyer Richard Cramer to represent them.
When contacted by BBC Sport, Castleford’s legal team said they would not respond to Diamond’s latest comments.
Solomona contract timeline
- 21 November 2015: Signs new three-year contract with Castleford
- 21 September 2016: Nominated for Super League’s Man of Steel award
- 25 September: Breaks record for most tries scored in a Super League season
- 25 October: Tigers chairman Steve Gill denies club sold the winger and says he is not for sale
- 24 November: Fails to report for pre-season training with Castleford, prompting club to say they will take legal action
- 28 November: Diamond confirms interest in player after saying he “resigned from playing rugby league”
- 7 December: Registered in Sale’s European Champions Cup squad despite his signing not having been confirmed
- 13 December: Sale announce Solomona signing, prompting Castleford to say they will take legal action
- 18 December: Makes Sale debut in 24-10 defeat by Saracens in European Champions Cup