The youngster has struggled to find a place in coach Xabi Alonso's plans this season.
It's been suggested Endrick could be loaned out in January and Guti says: "The fact that he has no opportunity, not even to warm up, and that in the last minutes Xabi prefers to bring Gonzalo (Garcia) on... This shows the current hierarchy in his eyes.
"Can he be decisive? You never know. There are always injuries, moments when the coach can bet on you, you score and you get into the dynamic.
"If by December, he still hasn't had his chance, the best thing for him would be to go on loan to continue to progress. For a young player, as we often said with Arda Güler, the most important thing is the minutes."
