PHILADELPHIA – In theory, having practiced against DeSean Jackson should help the Eagles’ secondary deal with him when they have to cover Jackson in a game Sunday.

“We know him well,” defensive coordinator Bill Davis said. “He’s got great speed, with great ability to catch the ball and adjust. We know he’ll be amped up to play us, like all guys are when they go back and play their old teams. One of the good things is, our defensive backs have covered him every day. I think it helps a little bit when you go against him in practice every day and you have a feel for him, as opposed to playing a talent like DeSean that you haven’t gone up against.”

That’s in theory. In practice, it’s not quite as simple as that.

“Game speed is totally different from practice tempo,” Eagles cornerback Cary Williams said. “Practice means nothing, man. Nothing. I expect him to be at his best. I’ll be at my best. He’s a gamer. I’ve seen him in practice and I’ve seen him in games. It’s two different speeds. So practice means nothing to me.”

The Eagles corners play on one side – Williams on the right, Bradley Fletcher on the left – so both will have to cover Jackson, assuming his shoulder injury permits him to play. So will slot cornerback Brandon Boykin.

Boykin agreed that Jackson plays faster than he practices.

“Then he’s coming back to Philly,” Boykin said, “so it’s going to be times two.”

The Eagles know Jackson is an emotional player. They expect his emotions to be running high Sunday.

“No question they are,” Williams said. “We’re well aware of it.”

A few years ago, when Williams was with the Baltimore Ravens, he and Jackson got into a scuffle during a game against the Eagles.

“I’m going to play my game,” Williams said. “I’m going to try not to penalize my team. I’m not going to go out there and do anything stupid.”