Samuel, who missed the Eagles' previous two games, practiced on a limited basis Wednesday and sat out Thursday's workout. He was at practice Friday, helmet in hand, but left after just 15 minutes.
"I was down today," Samuel said. "My main thing is just try to get as healthy as possible. Whether I'm out there or not, whatever I'm doing I'm just trying to get as healthy as possible."
Reid wouldn't call Samuel's situation a setback. The cornerback, who leads the NFL with seven interceptions this season, just isn't ready.
"It's like what I told you Wednesday, that he was going to give it a try and see how he felt," Reid said. "And so, it didn't feel very good on Wednesday, so we backed off of him. We're giving him treatment."
In the last two games, the Eagles' pass defense has fallen from 13th to 17th in the NFL. Against the Chicago Bears, the Samuel-less secondary allowed Jay Cutler to throw four touchdown passes, and against the Houston Texans, it allowed Matt Schaub to pass for 337 yards. Earlier in the season, Samuel missed a game against the San Francisco 49ers, and Alex Smith threw for 309 yards and three TDs.
"The last couple of games, I was proud of what (the rest of the secondary) did," Reid said. "But again, you're talking about Asante. He's a great player. Would you like him to be in there? Yeah, absolutely, you want him to be in there. But the other guys sure did a nice job. If Asante can go, he'll go in this game. And if he can't, then I have full trust in the other guys."
"I really don't need any practice," Samuel said, according to the Eagles' website. "My main thing is being healthy, but the more practice, the better. I would prefer to be out there running around a little bit more, but I'm just trying to do the best thing to get all the strength back possible and be ready to go."
Eagles offensive tackle Winston Justice also didn't practice Friday and is listed as questionable with a knee injury. Reid was asked whether Samuel or Justice was farther along in recovery.
"Well, I mean, Asante's done a little bit more than what Winston has, although Winston did some things today," he said. "I would just tell you they're both day to day. So they both worked, not a whole lot, but enough out there."
"He can play either side," Reid said of Dunlap. "But he's actually more comfortable on the right side."
The Associated Press contributed to this report.