The 24-year-old New Zealand international, who moved to Upton Park two years ago, has cemented his spot in defence in the Premier League, which has pushed teammate James Tomkins down the pecking order.
"I think one of the most impressive [players] has been Winston Reid, who hasn't really been in this country that long and in his first year suffered relegation with West Ham," Allardyce told Yahoo.
"The improvement of Winston and the consistency of performances he gave us as a central defender have been key to some of our results, because our defensive unit as a team and as individuals have been very good, so I think Winston has been very good."
Meanwhile, the Hammers are preparing to go up against Southampton on home turf tomorrow.
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