Initial fears surrounding a broken finger - sustained during Friday night's win over the Penrith Panthers at CommBank Stadium, had Moses racing the clock to be fit for the finals after undergoing surgery for the injury.
Moses, who has been replaced by Jakob Artur, has been instrumental for the Eels this season, with the club's chances at making the top four ahead of the finals taking a battering thanks to his injury.
The club said on Monday however that the star half could return in Round 24 if everything goes to plan, suggesting he may only need three weeks on the sidelines.
"The Parramatta Eels will be without Mitch Moses for at least three weeks to a finger injury," the club said in a statement.
"The halfback broke his finger in Friday's win over the Panthers and had surgery on it yesterday.
"He is expected to be fit to return to play by Round 24 at the earliest."
A three-week lay-off for Moses would see him miss games against the Manly Sea Eagles, South Sydney Rabbitohs and Canterbury Bulldogs, before potentially being available to play the Brisbane Broncos and Melbourne Storm in what is one of the NRL's most difficult runs to the finish line.
The club also confirmed Bailey Simonsson is out this week with a hamstring injury, having been a late withdrawal last week.
He is a chance to return in Round 22 against the Rabbitohs however, according to the club.