​Yankees rookie George Lombard Jr. left the second game of Saturday’s doubleheader against the Red Sox early due to right knee discomfort.The shortstop appeared to tweak his right knee during his at-bat in the second inning, in which he later singled, but remained in the game and hit again in the bottom of the third (line out).He was then replaced on defense in the top of the fourth inning by Amed Rosario.The team said that Lombard will undergo imaging on Saturday to determine the severity of the injury.In 23 games since being called up, Lombard is hitting .253 with two home runs and six RBI. Defensively, he’s had some issues with seven total errors.This is a developing story and will be updated…