The Welsh side come into the game following a very successful start to the season, which has seen them climb to 8th place in the Premier League, only one point behind Arsenal.
But the German defender understands the difficulty which Arsenal can face when the play Swansea.
Mertesacker told the official Arsenal website: "Swansea are a good, technical side - they can play shorter and longer balls to good effect.
"But we have to look at our game first and improve on the Everton performance. We have to respect our game as well as that of the opponent.
"December is here, and it's a very important month for us - let's start it as we mean to go on."
The centre-back also spoke of his personal excitement as they host Swansea.
"My first game last year was against Swansea, so it's always something special to face them.
"They are playing well - they have good possession and are doing similarly to last year, when they were impressive.
"It's important that we keep to our normal game plan and be ready to do something right from the start, especially in the final third of the pitch.
"We want to get the three points. The league is getting harder every year and every opponent is getting better, so we need to keep concentrating and show exactly what we can do."