Blue Bulls help out Kings
Props Martin Dreyer and Njabulo Gumede, hooker Alandre van Rooyen and lock forward Freddy Ngoza will join the Southern Kings with immediate effect.
All will move for the duration of the tournament, although the Blue Bulls Company (BBC) could call Gumede back if needed.
Current Blue Bulls players Dayan van der Westhuizen and Irne Herbst were amongst those loaned to the Southern Kings during the Super Rugby tournament.
"This decision will not only benefit the Kings, but SA Rugby as well and will of course give our players good exposure in a different environment and competition," said BBC High Performance Manager Xander Janse van Rensburg.
"We contracted all of them in the first place because we value their abilities, but can also not ignore the needs of the players and the bigger picture in SA Rugby.
"The BBC would like to wish all the guys well in the Pro14 and believe all of them will make a considerable impact for the Southern Kings."
Dreyer has played Super Rugby for the Bulls and Stormers, while Gumede is a former Junior Springboks prop. Van Rooyen and Ngoza played for the Blue Bulls in the National Provincial Challenge.
Janse van Rensburg also confirmed that Jacobie Adriaanse has been released to join the Golden Lions for the remainder of the season.
