YOU SAID:

I will not be playing catcher this year even though I've been playing for 6 years

INTO JAPANESE

今年は6年間プレーしているのに、今年はキャッチャーをしません。

BACK INTO ENGLISH

I have been playing for 6 years this year, but this year I will not be a catcher.

INTO JAPANESE

私は今年6年間プレーしていますが、今年はキャッチャーにはなりません。

BACK INTO ENGLISH

I have been playing for 6 years this year, but this year I will not be a catcher.