Complex sentence: During his stay with the "Che", however, Pérez would be often loaned, only amassing a few callups to the main squad and being released for good in January 2007, after which he resumed his career in the third and fourth levels.
Split into simpler sentences: During his stay with the "Che", however, Pérez would be often loaned, only amassing a few callups to the main squad and being released for good in January 2007. Subsequently, he resumed his career in the third and fourth levels.