Everton drew 1-1 at the Emirates on Sunday.
Wilshere said: "I'd say [Everton have been our toughest opponents this season].
"I remember last year [against them] it was probably our toughest game as well, we drew 0-0.
"They're a strong team, they've got a new manager as well so they play a different way but they're still just as strong.
"They took the game to us in the first half."