Lomax sealed the Eels' first win of Jason Ryles' tenure last Saturday when he kicked a golden-point field goal in Parramatta's 23-22 win over his former club St George Illawarra.
It was initially believed that Lomax had suffered bruising to his foot after he spent a good chunk of the second half limping.
But scans revealed late on Tuesday that Lomax had a minor fracture in his foot, with the 25-year-old set to miss the next six weeks of action, starting with Saturday's clash against Canberra in Darwin.
Bailey Simonsson appears the most likely option for Ryles to turn to in Lomax's absence.
The injury leaves Lomax at long odds to return to the NSW squad for State of Origin I in Brisbane on May 28.
Lomax was one of the success stories of the Blues' 2024 series victory, the ex-Dragons flyer featuring in every game, scoring three tries and kicking eight goals after being installed as the NSW goalkicker.
If Lomax's return to fitness goes to schedule he will line up for the Eels in round 11 against Newcastle on May 16, giving him just one match to press his claim for a recall.
NSW coach Laurie Daley is set to name his squad for the series opener on May 19.
Lomax's injury comes at the same time fellow incumbent NSW winger Brian To'o is sidelined with a hamstring issue, which is expected to rule him out until round nine.
Manly fullback Tom Trbojevic, who has played Origin as both a winger and centre, is also not due back until round nine after being sidelined with a medial ligament injury.
Daley will also be hoping Eels halfback Mitchell Moses can find some instant form when he returns from a foot issue.
Moses has been struggling with pain in his foot caused by a screw inserted during surgery last year and starred for the Blues in last year's series.
He is also due back in round nine and will jostle with Nathan Cleary and Jarome Luai for a place as a five-eighth or halfback in the Blues' set-up.
