Giants' Johnson strains shoulder, leaves game

SAN FRANCISCO (Reuters) - Veteran San Francisco Giants pitcher Randy Johnson injured his left shoulder on Sunday, forcing him to leave in the fourth inning of a 7-1 loss to the Houston Astros.

"It's a strain," the 45-year-old Johnson told Major League Baseball's official website (www.mlb.com). "I'm getting an MRI (magnetic resonance imaging exam). That's all I have to say."

Giants manager Bruce Bochy said the team would wait until after the exam, expected on Monday, to determine the next step.

"If there's anything going on, we'll give him some extra (rest)," Bochy said.

Johnson, the only active pitcher with more than 300 victories, accidentally flung his bat after striking out in the third inning and immediately grabbed his shoulder in discomfort.

The left-hander started the fourth inning but gave up two home runs and a single before making a throwing error to give the Astros a 4-0 lead.

After one pitch to the next batter, Johnson (8-6) called Bochy and the Giants trainer to the mound and left the game.

(Reporting by Gene Cherry in Raleigh, North Carolina; Editing by Greg Stutchbury)