Everton's hopes of staying alive in the hunt for a UEFA Champions League spot hang on their home clash with title-chasing City, with all eyes on centre-back Jagielka's availability as he has returned to fitness from a hamstring injury.
Martinez, though, failed to confirm the England international would be involved at Goodison Park, with Jagielka unseen since late February.
"He is fully fit for Saturday and that has always been the plan to get him fit for the Man City game. We are well on track on that," Martinez said.
"I will make a decision closer to the game if he is going to be on the bench, and see if there is an opportunity to give him some playing time, or the other way around.
"He is fully fit but to play 90 minutes it needs to be my decision depending on the players. It's just a team decision.
"He is fit, medically fit, but that does not mean he is going to get a place. Nobody has a place guaranteed in the team, not even the skipper."
