Steelers QB Ben Roethlisberger left Monday night's game in the third quarter. / Jason Bridge, US Presswire

by Nate Davis, USA TODAY Sports

by Nate Davis, USA TODAY Sports

Quarterback Ben Roethlisberger left Monday night's game with an injury to his passing shoulder after getting sandwiched by Tamba Hali and Justin Houston on a third-quarter sack against the Kansas City Chiefs.

Big Ben left the field about one minute into the second half. ESPN's cameras showed him being taken away in a golf cart in the bowels at Heinz Field with his jersey and shoulder pads removed.

Steelers coach Mike Tomlin said following the game that Roethlisberger was being medically evaluated at a local hospital. ESPN reported he suffered a shoulder sprain.

Roethlisberger, who mentioned he'd been dealing with rotator cuff issues in training camp, has always been susceptible to nagging injuries but has missed just four starts due to injury in the past seven seasons.

If he misses any significant stretch, an offense that's become increasingly reliant on his arm could be in serious trouble.

He completed half of his 18 passes for 84 yards and a TD in rainy conditions before exiting Monday night. Big Ben also surpassed the 1,000-yard rushing plateau for his career.

The Steelers entered the night 1½ games behind the Baltimore Ravens in the AFC North but have two games this month against their archrivals, who are currently without their signature player, linebacker Ray Lewis (torn triceps). The teams will meet at Heinz Field on Sunday.

If Roethlisberger can't play, Leftwich would likely start and be backed up by longtime reserve Charlie Batch.