Flores was a revelation for the Reds last season, providing eight assists and scoring eight goals for the club, before winning the A-League's top individual prize.

The Argentine's exceptional performances have made him the target of a number of foreign clubs, with sides from the USA and Japan linked with his services.

But in their bid to retain his services, Reds director Michael Petrillo told the Adelaide Advertiser the club has offered him a huge new deal.

"We've made it very clear Marcos is a required player... the three-year deal we've offered him would make him the highest paid Adelaide United player ever," Petrillo said.

Adelaide are understood to be awaiting a response from Flores on the deal, but rejected suggestions he was being shopped around to foreign clubs.

Petrillo also revealed the Reds were hoping to sign a foreign left-sided central defender to fill their overseas quota for next season.

The Reds are hoping to naturalise Brazilian-born Cassio before next season, in order to open up one more foreign spot in their quota.

Adelaide believe the shortage of left-sided Australian central defenders means they need to look abroad to fill that position.

"That's definitely a position we will fill," Petrillo said. "Rini (Coolen) would prefer a left-sided player but we'll have to see what's available.

Petrillo added: "There are a few players in Holland Rini is interested in. But we've decided to wait until May (before making any serious attempts to recruit) when we'll know if a player's contract is going to be renewed by their club."