Spoiler warning: Plot and/or ending details follow.
Matuzas commanded the USS Helios for an extended period, and took great pride in his ship. He was noted for his unorthodox and relaxed approach to command which, although causing concern among his superiors, got positive results and earned him a strong record of accomplishments. He was also noted for the number of officers who had gone on to outstanding careers after serving under him, including future Captain Daniel Okagawa and future Commodore Diego Reyes.
When Lieutenant Gabriel Lorca grew restless after serving as security chief for three years, his captain and mentor Matuzas suggested a billet at OT-4 on Tarsus IV. Lorca accepted, which earned him a promotion to lieutenant commander. (DSC novel: Drastic Measures)