A temporary block on friends would be a useful addition, especially if you are going to play them in a big cup match.

I could be potentially playing a friend in the champions league final. (Both at semi final CL at the moment).
At the moment he can view all my games friendlies, league and cup.
If I set up a friendly match to test tactics against another team then he can view it.
Worse still, he could arrange a friendly with me!
It is the equivalent of allowing your competitor to see an open training session!

I am debating whether to unfriend him as a result.
The only problem is then you cannot add the person as a friend again. He always sends boosters and skills points. It would seem unfair.

Then should be some sort of temporary block option for this reason.