InDaily understands a Qatari side has made inquiries with United about the availability of the Spaniard.
An Adelaide United spokesperson confirmed that there has been interest but no formal offer has been received.
Isaías gained Australian citizenship earlier this year which makes him a more attractive option for Asian teams. Some leagues in Asia have rules permitting one foreign player from another Asian country to be signed without impacting the broader quota on foreign signings.
The A-League has been toying with the idea of introducing a similar rule but it has yet eventuate.
Cashed up teams in Western Asia have a history of poaching the A-League’s better players. For example, Saudi side Al-Ahli paid $1 million to sign former Melbourne Victory captain Mark Milligan, only to release him six months later.
Isaías joined Adelaide United for the 2013/14 season and has played 158 A-League matches for the Reds, scoring nine goals along the way. He played every minute of every game this season and is widely regarded by commentators as the best defensive midfielder in the A-League.
He has one year left on his current deal with Adelaide, having re-signed during the 2016/17 season.
Loved by fans, supporters are often heard chanting “Sí, sí, sí señor” in homage to his cracking set piece finish in the 2015/16 Grand Final.
Help our journalists uncover the facts
In times like these InDaily provides valuable, local independent journalism in South Australia. As a news organisation it offers an alternative to The Advertiser, a different voice and a closer look at what is happening in our city and state for free. Any contribution to help fund our work is appreciated. Please click below to donate to InDaily.