Everton face the Latics in the FA Cup fifth round after the League One side knocked out Liverpool in the previous round.
While admitting that it will be a tough game, Jagielka has promised that the Toffees will not be bullied in the eagerly-anticipated tie.
"Being beaten through being outfought is something I don't think the manager of this club would ever let happen - and I would put my mortgage on it!" Jagielka explained to The Mirror.
"The last thing the manager and players want is to be left with a load of ifs and buts. The boys are desperate because we have been to Wembley a few times. The fans go ridiculous, half the stadium is blue, and they are brilliant occasions.
"We are not going to count our chickens yet because it will be a very hard game against Oldham, but we'd like to think we have got enough to get past them and have a shot at winning a trophy."
Jagielka joined Everton in 2007 from Sheffield United.