NEW YORK (Reuters) - The New York Giants suffered a devastating blow to their defensive department when cornerback Terrell Thomas picked up a long-term knee injury in the team's pre-season game against the Chicago Bears on Monday.

The Giants' leader in tackles and interceptions in each of the last two seasons will miss the next campaign after tearing his right ACL (anterior cruciate ligament) when he collided with team mate Jason Pierre-Paul toward the end of the first half.

The 26-year-old eventually limped off the field under his own power, but the extent of his injury was revealed in the second half as the Giants went on to record an impressive 41-13 victory that was tinged with a sour taste.

"It's devastating," New York defensive end Justin Tuck told a sideline reporter during the game. "He was primed to have another great year for us.

The fourth-year Thomas recorded 101 tackles and five interceptions last season, the best campaign of his young career.

His loss is the second prominent cornerback to go down for the Giants this month after first-round draft choice Prince Amukamara broke a bone in his left foot on August 6 and faces an indefinite spell on the sidelines.

(Writing by Jahmal Corner in Los Angeles; Editing by John O'Brien)