Which one is OK?
We will play a friendly match in the break of the international match.
We will play a friendly match in the gap of the international match.
We will play a friendly match in the sapace of the international match.

Question

Answer

We will play a friendly match during the break of the international matches

Answer

Do you mean: 
We will play a friendly match instead of an international match. 
OR
During halftime of the international match, we will play a friendly match.
?

Answer

We will play a friendly match in the break of the international match