PITTSBURGH -- Steelers safety Ryan Clark will sit out Sunday's preseason game in Denver because playing at a high altitude can trigger a red blood cell condition that caused him to lose his spleen and gall bladder after a 2007 game there.
Clark also didn't play in the Steelers' regular-season game in Denver during the 2009 season. He does plan to run before Sunday night's game, as he did last year, to test his reaction to being in the mile-high atmosphere.
Clark became seriously ill after playing in Denver on Oct. 21, 2007, losing more than 20 pounds and missing the rest of the season. He returned to play without problems in 2008 and 2009, and he re-signed with Pittsburgh after last season.
