The Reds have defended the fact they failed to lure their former star back to South Australia, with rivals Melbourne Victory trumping them
Flores, a cult hero and influential figure during his time with Adelaide, signed a two-year deal with the Victory last Wednesday worth a reported $AU1.1 million.
The Argentinean's decision caused uproar with the Reds' faithful who believed their club were in the box seat to sign the 2011 Johnny Warren Medallist after his contract with Chinese Super League club Henan Jianye was terminated by mutual consent.
In an official statement released by the Reds, salary cap restrictions and a difference in negotiations were listed as the reasons behind the club's failure to lure Flores back, as a group of wealthy Adelaide businessmen tried desperately at the 11th hour to back the club financially in a deal to no prevail.
The Reds' press release conflicted, however, with Flores' agent Ritchie Hinton's statement and an email the attacking midfielder sent directly to The Adelaide Advertiser which said no official offer was ever received.
Flores declared in his email that his first option was always to return 'home' to Adelaide and was disappointed his former employers did not 'appreciate' him as much as Melbourne did.
Kosmina, who was reluctant to discuss the Flores situation, said his current crop of players were more than able to be successful without the 2010-11 A-League Foreign Player of the Year.
"We can go on about it all day but Marcos is not here, there is no discussion, end of story. (The club) did everything ... it's gone, it's done," Kosmina said.
"I'm more than confident with the squad we got that we can be successful - there are good players in this squad. You can ask questions about Marcos or any other overseas player we might bring in, and the fact is these guys made a Champions League without any of that.
"We played some decent football and with some young kids too like Evan Kostopoulos and Teeboy Kamara. People should have every faith in the players we got here and anyone that comes in now will be the icing on the cake."
Kosmina did, however, understand Adelaide supporters' frustration with the failure to reach an agreement with Flores but said the Reds would search for an attacking midfielder similar to the 26-year-old.
"Some people would be unhappy and I can understand that, but you don't build your team around one player," Kosmina said. "You can't do that because if that player doesn't work what do you do?"
"I would like to find an attacking midfielder but I'm not going to dive in - we need to look at what's available."
Reds vice-captain Cassio was also unwilling to give his thoughts on his fellow South American's transfer.
"For me it's a waste of time to talk about Flores, I want to talk about the players we have here and how we should raise the players that we have," Cassio said. "We have the right players to show that we are really keen and strong to win the A-League.
"He is my friend, but he chose to go. Business is business. He said that stuff a year ago that business is business and I think he is right."
The diminutive Brazilian also played down suggestions that the interstate rivalry between Adelaide and Melbourne would become intensified due to Flores joining the Victory.
"It's all about Adelaide and Melbourne, it's not about him," Cassio said. "The rivalry and games are always big ... they are good for the fans and there's a good atmosphere around.
"But it's always about the teams and not about one player."