Melbourne Heart captain Fred has been ruled out for at least a month after straining his quad in his side's 2-0 win over Adelaide United.
The Brazilian, 33, was substituted in the 56th minute of Friday's victory and will miss four weeks because of the injury, the club have confirmed.
An MRI scan on Saturday confirmed the injury, with Fred to miss the Heart's clashes against Western Sydney, Melbourne Victory, Perth and Newcastle.
A shattered Fred went straight down the tunnel after being substituted against Adelaide, with injuries having played a big part since his return to the A-League at the start of last season.
He will return for the Heart in time to lead his side's charge towards the finals, with John Aloisi's men sitting fifth on the table.