Given:
There are 15 players on a soccer team.
Only 11 players can be on the field for a game.
We will find the number of groups of players of 11 players can the coach make.
Note: the position does not matter, so, we will use the combinations
We will use the following formula:

substitute n = 15, and r = 11

So, the answer will be:
The number of different groups = 1365