It's not only left tackle Michael Oher who's dealing with a major challenge Sunday. Oher is responsible for blocking Tamba Hali, a Pro Bowl outside linebacker. However, Justin Houston is a speedy bookend pass rusher who leads the Chiefs with four sacks. Rookie offensive tackle Kelechi Osemele said he believes the 6-foot-3, 258-pound Houston is the fastest outside linebacker he'll have faced so far. Hali dominated Oher in the playoff game two seasons ago, piling up two sacks, one forced fumble and seven tackles with one pass deflection. The Ravens may need some chip-blocking assistance from running backs and tight ends to limit the impact of this formidable front seven tandem.