Green moved to Loftus Road early in the close season, but the England international has lost his place to Julio Cesar in recent weeks.
Allardyce thinks that Green being relegated to the substitutes' bench so quickly is attributable to the short-term attitudes that plague modern football.
He told the Evening Standard: "It seems unlikely that we will be facing our former goalkeeper Rob Green at Loftus Road.
"I'm not privy to what has happened there but I would only emphasise the short termism in professional football these days.
"This game has no patience anymore, there's no time for forward planning and future development, it's all about month to month, game to game.
"All keepers make mistakes but from the outside it looks as though somebody then told them Julio Cesar was available so they went for it."
The Hammers take on Rangers in the last Premier League fixture of the weekend on Monday night.