South African lock Flip Van der Merwe has been withdrawn from the Barbarians' match with Fiji at Twickenham this weekend by the Bulls.
The Super Rugby side refused to release the player on short-notice after Van der Merwe was called into the squad to replace the injured Eben Etzebeth.
Originally selected to start in the second row alongside All Black lock Dominic Bird, Van der Merwe will now play no part in the fixture.
"Van der Merwe withdrew after not being released by Bulls. Short time frame to arrange replacement. #baabaas," read a tweet from the Barbarians' Twitter account on Tuesday.
The Blue Bulls Company (BBC) clarified the situation in a statement on Wednesday:
"This is a very important period of preparation for the 2014 Super Rugby season and a vital stage of our squad's pre-season planning, strength and conditioning," said Mr Barend van Graan, CEO of the BBC.
"Even more important though is the management of our players after a very long season and as such, the heightened risk of key players getting injured can severely jeopardize our and their Super Rugby campaign."
"According to Van Graan, the BBC has always, for a number of years, been clear that this period is an active rest and recovery period for their international players and that requests for matches like these need to be directed to the BBC through the South African Rugby Union (SARU).
"On Saturday evening the Barbarians directly approached Van der Merwe to partake and on Sunday evening informed the BBC per a text message of the player's inclusion in the team.
"The BBC then immediately informed Mr Steven Berrick, one of the organisers of the Barbarian match, that Van der Merwe has no permission to partake in the match against Fiji.
"It was a decision based on principle and BBC policy, made in the best interest of the Vodacom Bulls team," added Van Graan.
"Van Graan furthermore confirmed that the BBC earlier received a request (through SARU) to release JJ Engelbrecht to partake in this match, a request they also declined."
The Springbok has been replaced by retired former Ireland and Munster lock Mick O'Driscoll.
Barbarians (revised): 15 Santiago Cordero, 14 Frank Halai, 13 Gavin Williams, 12 Jean de Villiers (captain), 11 Charles Piutau, 10 Patrick Lambie, 9 TJ Perenara, 8 Duane Vermeulen, 7 Schalk Burger, 6 Steven Luatua, 5 Dominic Bird, 4 Mick O'Driscoll, 3 Matias Diaz, 2 Bismarck du Plessis, 1 Tendai Mtawarira.
Replacements: 16 Keven Mealamu, 17 Guillermo Roan, 18 Coenie Oosthuizen, 19 Manuel Carizza, 20 Luke Whitelock, 21 Martin Landajo, 22 Tom Taylor, 23 Willie le Roux.
Date: Saturday, November 30
Venue: Twickenham, London
Kick-off: 14:30 GMT
Referee: Pascal Gauzčre (France)
Assistant referees: Luke Pearce, Greg Garner (England)
Television match official: David Grashoff (England)