The Argentinian has formed a good partnership with John Stones in the veteran's absence.
Jagielka has been missing since October due to a knee injury (via Sky Sports), and in his absence Funes Mori and John Stones have formed a decent partnership at the heart of Roberto Martinez's defence. And the Argentinian explained that having had to wait for his opportunity, he is not going to let Jagielka take his place back lightly.
"He was injured and in my moment I had to come in and play and take advantage of my time on the pitch," he said.
"He is the captain but I have done my job so he has to come back again and play for a spot. We will both have to fight for a place."
The 33-year-old has been an unused substitute in the Toffees' last two games, and had to watch as Funes Mori gave the side the lead during their Capital One Cup semi-final first leg tie with Manchester City.
While Funes Mori has done well since being given a prolonged chance in the side, he has been part of an Everton team that have leaked quite a few goals that has resulted in them falling into the bottom half of the Premier League table. They have conceded three against Bournemouth and Leicester, and four in the defeat to Stoke.
And Martinez may well deem that the presence of his skipper is what is required to sure up the back four and help the club move back up the table.