ARLC chairman Peter V'landys says players can challenge their official market value and submit their own case to the salary cap auditor.
That process could affect the PNG Chiefs' pursuit of Hudson Young, after the auditor initially valued him at $1.1 million following their $900,000-per-season offer.
The valuation was later reduced to $1 million, still above what the Chiefs were prepared to pay.
The Chiefs' tax-free package could deliver more take-home pay than Canberra's offer, despite being $200,000 lower per season.
V'landys said exceptional circumstances could be considered, but warned: "We just don't want the salary cap rorted."
Canberra confirmed Monday it had withdrawn its latest offer to Young: a four-year, $4.4 million contract.
The Raiders said they wanted to keep him for his career and called the deal the largest in club history.
Negotiations had continued since June, and the club needed an answer by the end of October to plan ahead.
Young, 28, is recovering from an Achilles rupture and will not remain with Canberra beyond 2027.
He debuted for the Raiders in 2019 and has played 155 games, six Tests for Australia and nine State of Origin matches for NSW.
The Chiefs are preparing for their NRL entry in 2028.