Defender Cristian Derbyshire, 20, midfielder Simphiwe Masilela, 21, and forward Mpho Padime, 18, have all been taken to Spain and will be put through their paces by coach Abdeslam Ouaddou.
Left-footed centre-back Derbyshire arrived at Pirates from Panorama FC last year and was a key part of their successful Diski Challenge side, with his aerial ability in both boxes a major asset.
Padime contributed 10 goals and nine assists in a fantastic season for the Diski Challenge side, and big things are expected of the teenager, who will hope to emulate the likes of recently departed Relebohile Mofokeng, who has moved to top Belgian side Royal Union Saint-Gilloise.
The hard-working Masilela is another player who played a big role for the reserve team and deserves his chance to impress in pre-season.
Pirates are due to face Spanish side Cordoba in a friendly on Wednesday.