'Latics' sack assistant manager
Rhodes, 54, had been back at the club for just four months before seeing his contract terminated.
He joined the coaching staff as Frankie Bunn was appointed first-team boss in June - the duo had played together at Oldham between 1988 and 1990.
Rhodes also worked with the 'Latics' as a goalkeeping coach in 2002.
Oldham sit 12th in League Two after 16 matches and face Northampton on Saturday.