Nieuwenhuis was playing very well as a rookie before slumping badly and then suffering a tear of his right foot's plantar fascia. He was injured playing at Triple-A Buffalo while running the bases, per the official team site.
The youngster was at one point hitting close to .300 before having a horrendous June that saw him go 4-for-38 with just one extra base hit.
On the year, Nieuwenhuis ended up with a .252 average to accompany seven home runs and 28 RBI. The 25-year-old ended up losing some playing time when Jason Bay came up and Jordany Valdespin started making a name for himself.
The news comes down the same day the Mets decided to place Johan Santana on the 15-day DL, most likely putting an end to his campaign.