By C. Trent Rosecrans
Hernandez, the 2010 Cy Young Award winner, had allowed seven runs (five earned) on 12 hits in 3 1/3 innings.
The ball hit off his right forearm and appeared to be in pain as he went directly to the visitor's clubhouse.
The official diagnosis is a contusion, which would be a relief for the Mariners, even though Hernandez was likely making his last start of the year anyway.
Rangers starter Alexi Ogando also left the game early, but his departure was planned. Ogando threw two perfect innings to start the game and is likely to return to the bullpen for postseason.For more baseball news, rumors and analysis, follow @eyeonbaseball on Twitter or subscribe to the RSS feed.