Harrison, who was named Saints’ player of the month for December, saw off competition from Saracens duo Mako Vunipola and Billy Vunipola as well as Bath’s Leroy Houston.
The competition was judged by former England prop and ITV pundit David Flatman.
And Flatman said: “This guy is Northampton Saints’ archetypal squad player. But guess what, Calum Clark got injured, Teimana Harrison came in and he’s been absolutely outstanding.
“There were some amazing individual performances to begin the year with four players in great from at the breakdown for their clubs! But, there has to be a winner and this month I am awarding the prize to Teimana.
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“Along with Mikey Haywood he’s been one of the most influential players at Northampton Saints, growing up some big wins and some massive performances from him.”