Tim Membrey, Max King and Dan Butler have each been charged with Engaging in a Melee following St Kilda's match against Gold Coast on Saturday 8 May at Metricon Stadium.
The trio can each accept a $1000 sanction with an early plea.
A first offence for Engaging in a Melee is a $1500 sanction. An early plea enables the player to accept a $1000 sanction.
Suns Oleg Markov and Sam Collins also received fines from the MRO, while Touk Miller can accept a one-match sanction with an early plea after a separate incident involving Nick Coffield in the second quarter.
The club has accepted the MRO's sanctions.