Flores hobbled out of Monday's 2-1 win over Sydney FC at the SFS with the hamstring problem and everyone at Hindmarsh is keeping their fingers crossed that the damage is not too severe.

Reds medical staff are hoping Flores will be out for no more than two to four weeks, meaning he would miss A-League encounters with Gold Coast United, Wellington Phoenix and Melbourne Victory.

"We will find out today but the current estimate is no more than a month," United spokesman Dom Rinaldo told the Adelaide Advertiser.

Flores has been a big hit for the club and has played a key part in the side's unbeaten start to the campaign.