Similar to Jose Fermin, Juniel Querecuto is a fine depth piece when your season is washed, but for a team trying to compete next year, his role is obsolete.
At 31 years old, they aren't waiting for him to blossom as a player filled with potential. He is 0-11 in St. Louis this year, and he doesn't give the Cardinals any advantages defensively as well. He primarily plays third base and second base, two positions that the Cardinals have no need for more depth at.
Even if the Cardinals do not think Saggese, Prieto, Dunn, or others are ready for big league action come Opening Day, Querecuto is so far down the pecking order depth-wise that the Cardinals do not need to roster him. By the time his spot would be called upon, I'm sure one of those promising internal options could answer that call.