Travis Long's No. 57 jersey was not going to be displayed in Philadelphia sporting goods stores this season, but there was considerable optimism about the linebacker in the team's headquarters this summer. So when it was learned that Long tore the anterior cruciate ligament in his left knee in the final preseason game, it left the Eagles without a player who was expected to be a valuable reserve.

It also made two backup linebackers even more noteworthy: inside linebacker Casey Matthews, who continues to survive, and first-round pick Marcus Smith, whose development requires patience.

Long could have helped the team at outside linebacker, inside linebacker, and on special teams. He would likely have backed up Connor Barwin, who defensive coordinator Bill Davis said wore "more hats" than any player on the defense. And he would probably have served as the fourth inside linebacker, a position at which the Eagles lacked depth.

"It's disappointing. You feel for him," general manager Howie Roseman said. "He's been a tremendous worker in getting back [from injury]. You see on the field the potential he has."

Without Long, Smith might become Barwin's backup. The Eagles selected Smith knowing he would take time to develop, but Smith's lukewarm preseason did not generate many supporters.

The Eagles do not have a time line for production. They just wanted to see growth. His pass-rush skills remain a major work in progress while Smith relies more on his athleticism. Davis said during the preseason that "the game is moving too fast" from Smith's perspective.

"Obviously he's a talented guy," Roseman said. "He's got talent. He's got length. He's got size. He's got athleticism.

"But it's all new when you're talking about someone coming into a new environment, trying to learn a new scheme. Do we hope he can contribute as a first-round pick? Yeah, certainly, we'd like that. But I think the story has yet to be written on it."

Long was the only backup outside linebacker who could also play inside, which meant the team had no choice but to keep four inside linebackers. Matthews was a beneficiary, and his versatility and understanding of the scheme gave him the edge to stay in Philadelphia for a fourth season.

"He can play inside. He can play outside. He can play a bunch of spots on special teams," Roseman said. "And when you're looking at the back end of the roster, you're looking for versatile guys who can do a bunch of things. Casey's shown he can play two spots, inside and out, and play a role on special teams."

Inside linebacker was the only position on offense or defense in which the Eagles did not add a player during the offseason. They tried during the draft, but the Eagles did not see value when they selected. So they relied on the development of Matthews, Najee Goode, Emmanuel Acho, and Jason Phillips.

When it became clear that outside linebacker was stronger than inside linebacker, the Eagles looked at players who could do both. That was Long. And now the Eagles are experiencing the result of lacking depth at the position.

Roseman said it's "hard to be perfect in the offseason." Long helped them cover the imperfection, which is more pronounced after the injury.

"It's a spot we looked at - we tried to upgrade and address - but we also didn't want to reach and do something we didn't think made sense," Roseman said. "Sometimes, it's the nature of the business. You're not going to always get what you want."

Extra points

The Eagles signed the following players to the practice squad: offensive linemen Josh Andrews and Kevin Graf, defensive lineman Wade Keliikipi, safety Ed Reynolds, linebacker Emmanuel Acho, wide receiver Will Murphy, wide receiver Quron Pratt, and running back Matthew Tucker. Each player spent the preseason with the Eagles, who still have two spots remaining on the practice squad. . . . Wide receiver Damaris Johnson was claimed off waivers by the Houston Texans, and defensive lineman Damion Square was claimed by the Kansas City Chiefs. Both players were waived by the Eagles on Saturday.