There's no confirmation from CCFC and since the announcement by Gibraltar an unofficial source has suggested that the game might be in doubt.
Later that week Cardiff are playing Charlton in Seville.
Gibraltar's national side are not affiliated to FIFA or UEFA so can play friendlies against club sides.
At the moment they are competing in the Island Games where they are in a group with Ynys Môn, Alderney and the Isle of Wight.
City have officially confirmed friendlies at Yeovil and Bournemouth and a home game with Parma. The matches in Spain have not been announced by CCFC but by Charlton and the Gibraltar FA.