The Cubs acquired Peterson from the Mets on Wednesday in exchange for infielder Cole Mathis (undisclosed), Jeff Passan of ESPN.com reports.
Peterson had endured a rough season with the Mets, turning in a 6.09 ERA and 1.65 WHIP in 68 innings across 16 appearances (eight starts). However, the Cubs will gladly take all the rotation arms they can get at this point, as Edward Cabrera (hamstring) and Ben Brown (neck) became the fifth and sixth Chicago starting pitchers to land on the injured list Wednesday. Peterson is expected to provide immediate aid to the rotation and could make his first start with the Cubs as soon as Friday at Milwaukee, after he threw 79 pitches Sunday in his final appearance with the Mets.