After defeat to Perth Glory on Sunday, Kossie told the Sydney Morning Herald: "We've had three or four players who have been shopped around to other clubs by their agents, there's been indecision and, to be honest, it's probably been playing on their minds a bit and it's affected their performance.
"This is something we really need to look at. I understand the rules will help the new teams coming in, but losing players like this is crazy. We're only eight games into the season and all of a sudden you've got players talking about where they're going to be playing in 25 games' time.
"It's ridiculous. It certainly doesn't create stability, which is so important in professional sport. I'm not going to say who in particular is struggling, but we've had a few players sniffing around at other clubs and now there's all this stuff going around in the back of their minds."
Kosmina roared: "All the agents are doing is shopping blokes around to the highest bidder, and I don't think they're acting with integrity.
"You go into the market and it's a complete free-for-all at the moment. It's outrageous. It's a hard one to judge, so we're concentrating on keeping the players we want first, but then you find agents shopping them around.
"To be honest, I think some of the agents don't even pass the message on to their clients when it doesn't suit them. An agent is always going to be lining his own pocket first. I don't think too many are concerned about the welfare of their clients, unless it involves getting the player more, which gets them more."