"If he is going to be third or fourth wheel then he might as well look elsewhere," Brown told the Herald on Sunday. "We told the Warriors that when he re-signed with them.
"If they did sign Green we would have to reevaluate."
There was interest in Hingano from several clubs before he signed an extension to remain at Mt Smart earlier this year.
Warriors chief executive Cameron George denied the club was nearing a deal with Green and insisted they are committed to Hingano.
"Ata's signed with us," George said. "I have seen reports linking us to Blake Green but that is all. Green is contracted to Manly for next year as far as I know.
"Reports that we are close to signing Blake are not accurate.
"If he or any other player were available we would consider them but there is nothing to report there."
George's predecessor Jim Doyle negotiated Hingano's re-signing earlier in the season but the new boss is more than happy with that decision.
"Ata is a big part of the club -- he was extended for two more years because we see him as a big part of our future," George added.
Green is reportedly poised to join the Warriors on a three-year deal worth around $2m.
A bigger money one-year deal might make sense, providing insurance if Hingano wasn't ready for a full season as a starting player or if star halfback Johnson wasn't back to full fitness. The longer term arrangement is either over-paying on halves or demonstrating a lack of faith in the youngster.