Ware, who has never missed a game since Dallas drafted him in 2005, suffered a strained right quad in the first half of last Sunday's 31-16 win over Washington.
Cowboys owner and general manager Jerry Jones says the team will be conservative with Ware's injury.
"This medical thing is at best ambiguous, especially if you're dealing with soft tissue type injuries or, for that matter, anything that relates to ligaments or muscle," Jones said Tuesday morning on 105.3 The Fan [KRLD-FM]. "So he's got that quad. We'll be pretty conservative with that because we know how bad we're going to need DeMarcus down the road, not that we don't need him against Philadelphia.
"It could be that he has the ability to go and has the playing ability to go on a certain basis as early as this weekend against Philadelphia. On the other hand, we may want to be conservative and make sure that thing gets in better shape."