Moyes has decided to wait until his Everton contract expires this summer before making a decision on his future.
Jagielka has insisted that the Toffees will not be affected by doubts surrounding their manager's future and are focused on chasing a top-four finish alongside a cup run this season.
He told The Sun: "At the end of the day, if we do win the cup and he doesn't sign, it will still be a fantastic feat for the players.
"We are a very close squad and we get on very well. As much as we go out there to do it for the manager, we do it for each other as well. Obviously, the fans, too. We had a good following today and the fans are brilliant, too. So there is more than one person there to play for.
"We haven't done too bad in the ten years or so that he has been here. It's not like we have under-achieved. If anything, we have slightly over-achieved in terms of budgets and transfer funds. He has made decisions that he wants to make. He has come out in the press and said he will not sign anything until the end of the season and that is fine with us."
Everton were forced to a fifth-round replay by League One side Oldham Athletic last weekend following a 2-2 draw at Boundary Park.