ALAMEDA -- Neither linebacker James Harrison nor strong safety Troy Polamalu practiced for Pittsburgh on Thursday, meaning the likelihood of the two, who have a combined 11 Pro Bowls and six All-Pro selections, missing Sunday's game against the Raiders seems fairly certain.Especially with the Steelers embarking on a bye week after playing the Raiders, which would give the two important cogs of their defense an extra week to rest.Not that the Raiders think their potential absence would change Pittsburgh's defensive philosophy much, if at all."The scheme is still the same," said Raiders offensive coordinator Greg Knapp. "But what it does help is it gives us a little clearer picture. Because Polamalu doesn't always line up where you think he's supposed to be, because he's got such great intangibles and speed that he gives you some looks that tell you one thing, but you actually get another. That doesn't happen as much when he's not in the game."GUTIERREZ:Knapp: We need some perspective and patienceAnd Harrison?"His presence as a pass rusher definitely is felt, no doubt about it," Knapp said. "They still have good edge pass rushers, though. The rest of the group theyve got, it still gives you a big challenge. But hes very unique, hes very special."Said tight end Brandon Myers: "Troy, hes the type of player that youve got to know where hes at at all times. So were preparing like hes going to play. Same with Harrison because hes a dominant player. Youve just got to be ready for whatever. I dont think it necessarily changes them that much if theyre not in there."