Sparks, in his first practice Wednesday, played with the second unit while fourth-round pick Kareem Larrimore was with the first team.
Sparks, 31, has not played since the 11th game last season because of a groin injury he suffered while playing with the New York Giants.
"I think he's a little bit rusty just from the standpoint of the conditioning part of things," Campo said.
"But hopefully in two or three days, he'll get a chance to get his legs back underneath him, and we'll go to work."
Campo and his staff will put Sparks through extra meetings to get him ready.
They will decide Friday, after he has been through three practices, how much he will play, and in what situations.
"We limited his reps because we want to make sure we're not pushing it too hard here because, coming off him not participating, you want to make sure you don't end up with a pull or something like that," Campo said.
Hot on Eagles
With temperatures in the area hovering around 100 degrees, the Cowboys hope the blazing heat they have endured during preseason will help them against Philadelphia. Sunday's game at Texas Stadium will start at 3:05 p.m.
Coach Dave Campo talked to the players about that Wednesday and had them run some sprints after practice.
"I'd like to feel like us practicing in the heat is an advantage, but we'll find that out in the fourth quarter," Campo said. "There's no question that it's tougher to concentrate, it's tougher to focus when you're tired and hot, and that's exactly what happens in the fourth quarter."
Eagles coach Andy Reid said Wednesday his team is taking precautions by drinking extra fluids during practices this week.
Cornerbacks Charlie Williams (staph infection) and Dwayne Goodrich (hamstring) are the only Cowboys definitely out with injuries for Sunday's game.
Cornerback Mario Edwards, who missed the last two preseason games with a strained left hamstring, practiced with the second unit Wednesday and should be a gametime decision, coach Dave Campo said. How much tight end David LaFleur (pelvic bone irritation) and defensive end Greg Ellis play will be determined by how they feel during the game, Campo said.
The Cowboys signed quarterback Anthony Wright on Wednesday, giving them five practice squad players. Wright spent his rookie season last year in Pittsburgh. ... Cowboys defensive coordinator Mike Zimmer enlisted head coach Dave Campo, the former defensive coordinator, to work some with defensive backs during Wednesday's practice. "I'm glad I get a chance to do it," Campo said. "I don't get to do it very often, and that's my favorite thing."