When he woke up the next day, Smith was relieved. The hamstring did not feel seriously damaged. An MRI on Friday morning confirmed that Smith's hamstring was strained.
"It's not as bad as I thought it was," Smith said Friday. "Three weeks is probably the most. I'll definitely be ready for the Falcons game. I'll try to be back for the last preseason game."
The Eagles chose Smith, 23, with the 26th pick in the 2014 NFL draft. He did not earn much playing time as a rookie. After working in training camp in 2014 as an outside linebacker, he was moved inside during the season because of injuries to teammates. For the season, Smith was on the field for 68 defensive plays.
But during the offseason, starting outside linebacker Trent Cole was released and Brandon Graham, the top backup, was promoted to Cole's spot. That left an opening for Smith to gain some playing time. He played well in the Eagles' preseason opener against the Indianapolis Colts on Sunday.
"I don't think it sets me back at all," Smith said of his injury. "I just think it's something unfortunate that happened. I'm just going to rest and get the proper recovery and do what I have to do to get back."
In Smith's absence, Bryan Braman will get extended playing time. Brad Jones, who can play inside and outside linebacker, could also fill in. Another possibility is defensive end Vinny Curry, who has been working at outside linebacker in recent weeks.
"I'm excited about seeing Vinny in that role," Eagles defensive coordinator Bill Davis said.
But Smith's goals for the season haven't changed.
"I'm just worried about getting healthy," Smith said. "The third linebacker job, that's still my goal. That's still what I want to do. I still want to help the team."