Maclin was cleared by doctors earlier this month after being stricken by an unknown illness during the offseason. Smith, signed away from the New York Giants, underwent microfracture surgery in December. Both were placed on the Eagles' active roster.
Coach Andy Reid said Maclin and Smith were both limited at practice Saturday, and will be evaluated on a daily basis to determine how far they can go.
"If they make it through the evening fine, without any problems or setbacks, then we'll add some more onto it (on Sunday)," Reid said. "And then we'll just keep on going from there and see what happens. But really, I can't tell you the date right now on either one when they'll be ready to play."
Maclin and Smith both said they expect to be in uniform when the Eagles open the regular season Sept. 11 in St. Louis.
"It felt good," Maclin said. "I was kind of getting my feet back under me a little bit. Over the next few days, we're going to manage my reps and let me get used to it. I feel alright, conditioning wise. It's just being out there, running routes. I haven't done that in a while, so there's definitely some work I need to do.
"Like I said, I think I'll get back to my normal self pretty soon."
Maclin, 23, caught 70 passes for 964 yards and 10 touchdowns last year and has 125 receptions for 1,726 yards and 14 scores in two NFL seasons. He has missed only one game as a pro. A sore foot kept him out of a game vs. San Francisco his rookie year.
"I think this week, they're going to ease me into it and monitor my reps and then they'll let me loose next week," he said. "I don't know what that entails, but I think I'm going to back to being the same guy I was before this."
Smith, 26, caught 220 passes for 2,386 yards and 11 touchdowns in four seasons with the Giants, including 107 receptions for 1,220 yards in his 2009 Pro Bowl season. He's one of six former Pro Bowl players the Eagles added during the offseason.
Saturday's practice was Smith's first as an Eagle.
"It was great just to be back out there with my teammates and hearing the calls from (quarterback Michael) Vick," he said. "It was really fun."
Smith said he's still not 100 percent, but is getting close.
"It'll take me a few weeks, but I feel really good right now," he said. "I don't feel like I'm laboring or I can't cut. I'm doing good so far."
The Eagles finish the preseason Thursday night against the New York Jets in East Rutherford. Reid wouldn't speculate whether Maclin or Smith will play in that game.
"It all comes with time," Vick said. "We just have to continue to get reps. Jeremy and Steve have to shake the rust off and get back into football shape. It'll take about a week or two.
"But, they'll be alright."