Forward Zarate moved to Loftus Road on a six-month loan on Tuesday, bringing an end to an unhappy short stay at West Ham - for whom he scored two goals in seven league appearances.
QPR sit 16th in the Premier League table, just two points above the relegation zone, and manager Redknapp made it known in recent weeks that an attacker was top of his January wish list.
And Green believes former Inter and Lazio man Zarate offers a different option to the likes of QPR's top scorer Charlie Austin and Bobby Zamora.
"Zarate's scored goals wherever he's been," Green told Sky Sports.
"He's had a lot of loan signings and I'm sure he sees this as a chance to get some playing time and get some goals.
"He adds something different to Bobby Zamora and Charlie Austin. He's a more diminutive striker and another option for us off the bench or from the start."
QPR have yet to pick up a point on their travels this season and face a trip to improving Burnley on Saturday.
And Green believes the clash at Turf Moor could be vital in QPR's bid to avoid the drop.
"The game with Burnley is huge," he added. "We can put some breathing space between us and them below us but they can go above us if they win.
"It's a real six-pointer and we want to buck the trend of our bad away results this season."
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