Thanks to the sprained ligament in his right knee, the possibility exists that L.J. Smith's career with the Eagles is over.

If that's the case, we can look back at a five-year period that has been better than many people may believe, and we can look forward to what the Eagles might do to fill the need at tight end next season.

Smith, a second-round draft choice, can become a free agent after this season and has been saying for some time that he doesn't think he'll be back in Philadelphia next season. He has never said that he doesn't want to return, and he kept that door open even yesterday before disappearing behind the door to the players' lounge.

"It feels a little weird to be here and not know my future, and I don't know who to look at and ask the questions to," Smith said after his teammates finished practice in preparation for Sunday's game against the Dallas Cowboys. "I don't know who to get answers from. That's the weird part."

Smith, in his fifth season, has never been considered an elite tight end like San Diego's Antonio Gates or Kansas City's Tony Gonzalez. But in 2005 and 2006, he was among the top 10 at his position.

That, of course, has not been the case this season. Slowed by a groin injury that required two separate surgeries, he has just 22 catches for 236 yards and one touchdown. He missed three games because of the groin injury, and now he figures to miss at least the next two because of the knee injury. He said he could not imagine a worse season.

"I've been through injury, and I've been through my first real taste of media criticism," Smith said. "I've seen it all this year."

It will be interesting to see how the worst season of Smith's career affects his value on the open market in March. From 2004 through 2007, he caught 145 passes for 1,670 yards and 13 touchdowns. In that same time frame, Indianapolis' Dallas Clark, the only tight end taken in the first round of the 2003 draft, caught 92 passes for 1,278 yards and 13 touchdowns. Smith has 67 more career receiving yards than Clark.

The only tight end from the draft class of 2003 that has been more productive than Smith is the Cowboys' Jason Witten, who has vaulted into the class of the elite. Witten, taken eight picks after Smith, in the third round, has 80 catches for 955 yards and seven touchdowns this season.

Smith, 27, doesn't think his injuries this season will hurt him all that much in free agency.

"I'll be healed up soon," he said. "This isn't an ACL tear or anything like that."

Smith had missed just one game in his career before this season, and he benefits from the fact that he is probably going to be the best available player at his position.

Smith said he didn't feel he had come close to accomplishing the things he wanted to when the Eagles drafted him.

"What you want to do is win the Super Bowl and go to Pro Bowls," he said. "I fell short in both categories. My goals weren't accomplished."

If the Eagles decide to go in a different direction at tight end, they'll have to decide whether they think rookie Brent Celek can fill the void. After an impressive training camp, the fifth-round pick out of Cincinnati has been OK, catching eight passes for 75 yards. He would certainly be a question mark if elevated to a starting position next season.

The Colts' Clark is also eligible for free agency, and he'd certainly be an interesting addition if the Eagles could sign him. As for the draft, Notre Dame's John Carlson, Texas A&M's Martellus Bennett, Wisconsin's Travis Beckum, and the Missouri duo of Martin Rucker and Chase Coffman are considered among the best in the country.

Smith said he hoped to play again this season and is eager to see what happens after that.

"I'm not anxious to leave," he said. "I'm anxious to get it all figured out. I've thought about not being here and I've thought about being here."

Contact staff writer Bob Brookover at 215-854-2577 or bbrookover@phillynews.com.