We study the morphology and masses of extremely red galaxies (EROs) within the GOYA survey (Galaxy Origins and Young Assembly), by combining optical data (UBVI) with near-infrared data (JKs). The initial K-band selected catalogue contains some 2500 sources over 4.5 arcmin2, of which 113 sources have F814W-Ks>=4 and are classified as EROs. In order to make use of the higher spatial resolution of the HST images, we limited our sample to objects which have F814W-band detection. Employing a by-eye classification, we assign one of the following classes to these objects: compact (39), bulge+disk (13), pure disk (25) and irregular or merger candidates (14). For 16 objects we were unable to assign an unique class and an additional 6 objects were excluded from our sample for other reasons. Based on the five morphological classes we look for distinct characteristics in the stellar mass evolution and attempt to separate between a burst component and a second star forming component, characterised by an exponential declining star formation rate (SFR). The results show that the total stellar masses do not differ significantly among the different morphological types, each class has members with M>1011Msolar. For most of the EROs the best fit represents a single-age population, a second starforming component would contain less than 10% of the total stellar mass.