Another Donkey in the Middle

Avi, Beni, and Gadi played "Donkey in the Middle" - at any given moment, someone is in the middle, trying to catch a ball that the other two are passing to each other.
If he succeeds, one of the other two replaces him. After the game, Avi said that he was in the middle 8 times,
Beni said he was in the middle 4 times, and Gadi forgot how many times he was in the middle.
They also remember that Beni was the last one in the middle. Describe all the possibilities for the number of times Gadi was in the middle,