The Sun Dream Team offers seven variations of team formations:
How to change formation
Changes to formation can be made at any time during the season. As long as you have a transfer available to accommodate a change in formation. For example if your formation was set to 4-4-2, you could only change the formation by making a transfer swapping a midfield player for a striker to accommodate the change to 4-3-3. This can be managed from your Team Hub.