TACX Jockey Wheels & Shimano Magarange Derailleur

I may have made an error.

I ordered a TACX ball-bearing jockey wheel set last week for the Shimano 7
speed range, and I believe that both pulleys come with 11 teeth. I've just
noticed that my current Megarange Derailleur has a larger bottom-wheel,
which has 13 teeth.

Will the loss of two teeth cause any problems if I replace it with the TACX
wheel?

Thanks in advance, any comments would be appreciated.

Bob,