Niese will undergo a minor surgery on his left knee, James Wagner of the New York Times reports.

EDGE Analysis

Fortunately, the recovery process for the surgery is expected to be quick, giving the Mets hope that Niese will be back sometime in mid-September. Until he's back, Robert Gsellman will be a part of New York's rotation. Before injuring his knee, Niese had posted a lofty 5.50 ERA and 1.59 WHIP over 29 games, both of which are well above his career averages of 4.07 and 1.38, respectively.