The Germany international appears to be rediscovering his best form after an injury-hit debut season in Serie A but the Viola boss is demanding further improvement
The Germany international endured an injury-ravaged debut season at the Artemio Franchi following his move from Bayern Munich last summer but looked like his old predatory self in controlling a pass from Federico Bernardeschi before slotting home what proved to be the winner in La Plata after just 29 minutes of play.
Montella liked what he saw from his front two but claimed that he was not fully satisfied with the pair.
"Mario and Bernardeschi moved well together, but they can still improve - and they must do that," the former Italy international told reporters after the 1-0 friendly win. "On occasion, they did well but they can do better.
"But we played a good game. The team sacrificed a lot, but the spirit of the guys pleased me and this was the most important thing."
Gomez joined Fiorentina from Bayern for a reported €20 million and penned a four-year contract with the Viola.