A 6-1 mauling at the hands of Germany back in October 2012 remains fresh in the minds of Giovanni Trapattoni's squad, despite two fixtures having been taken in since then.
A third arrives on Wednesday, as Ireland face Poland in a friendly, before competitive action returns in March.
McCarthy is looking for the Irish squad to take a midweek fixture as seriously as possible, with it important for positivity to be returned to the camp ahead of crucial clashes on the road to Brazil 2014.
Ireland sit third in their qualifying group at present, with six points taken from three outings.
"We need to try and put it (the Germany defeat) to the back of our minds and try to really kick on now," said McCarthy.
"Poland's a good test for us and then next month, we have got the two qualifiers, and we need to go into those games and try to be as positive as we can.
"It's not going to be easy. Sweden and Austria are two massive games and two tough games."