Farassoo I'm thinking about my soccer game next week.

FarassooI'm thinking about my next week soccer game.

No, that doesn't work.

http://dictionary.cambridge.org/grammar/britis

Thank you teechr

So in English you say
I was thinking about the soccer game next week(the game which will be next week)
and
I will think about the soccer game next week.(I don't want to think now!)

You're welcome.

FarassooI was thinking about the soccer game next week (the game which will be played next week).

Try,
I was thinking about next week's soccer game.

FarassooI will think about the soccer game next week. (I don't want to think now!)

OK.

Thank you so much teechr
I'm a beginner and I'm trying my best not to translate sentences from my own language.

I have another question. In my own language when we are speaking, the sentences are not always grammatically correct. I want to know if you use this one in speaking:
The game will be next week?! I mean without played.

and this one:
my next week's soccer game

FarassooThe game will be next week?! I mean without "played."

Try,
Is the game on next week?

Farassoomy next week's soccer game

Try, e.g.,
"I wont be at my soccer game next week."