Pierre Garcon, shown with fellow wide receivers Santana Moss, left, and Anthony Armstrong in a preseason game, is back at practice but his toe ligament injury continues to hamper him and threatens to end the offseason pickup’s season. (John McDonnell/The Washington Post)

The injury that has threatened to wipe out most of the season of the Washington Redskins’ would-be top wide receiver isn’t a shattered arm or a shredded knee. It is an ailing second toe on Pierre Garcon’s right foot.

It may seem innocuous, but Garcon’s injury — a plantar plate tear that involves a torn ligament near the second toe — is in­cred­ibly limiting for a player whose on-field success depends largely on the ability to accelerate, cut sharply and move swiftly.

One medical expert not involved in Garcon’s treatment said this week that the injury could be relatively debilitating when the ligament is torn and the toe is unstable.

“If it’s not stable, it’s analogous to a torn ACL in the knee,” said Phillip K. Kwong, a foot and ankle surgeon at the Kerlan-Jobe Orthopaedic Clinic in Los Angeles. “If the toe needs to plant and cut, you won’t have the stability to do that, to change direction. You don’t have the stability to hold the toe without pain.”

Garcon, who was signed to a five-year, $42.5 million contract as a free agent in March to be the leading man in the team’s wide receiver corps, has played in only three of the Redskins’ nine games this season. But he resumed practicing Monday, following the team’s bye week, and Coach Mike Shanahan has left open the possibility of the wide receiver returning to the lineup Sunday against the Philadelphia Eagles at FedEx Field. Garcon was also a limited participant in Thursday’s practice.

What is a plantar plate?

“It’s gotten a little bit better,” Garcon said this week. “But when you go back to running on it, you can feel pain.”

Garcon said his foot bothered him during the preseason but he kept playing. He then felt a pop on his 88-yard touchdown catch and run during the Redskins’ season-opening win at New Orleans. He has played in only two games since then, most recently on Oct. 7, totaling only four catches for 44 yards.

Garcon was examined by Charlotte-based foot specialist Robert Anderson on Oct. 24, and has said that he and team officials will have to decide whether he should undergo surgery, which would end his season.

But Garcon has said that he would like to put off surgery until after the season or avoid it completely, if possible, saying his understanding is that surgery is not guaranteed to fix the problem.

“It’s going to be pain regardless,” Garcon said earlier this week. “So we’ll have to look at options every week, day to day, monitor it, go from there. But I really don’t want to get surgery. That’s where I stand on that. But we have to monitor it every day.”

Kwong spoke in general terms about the injury because he has not been involved in Garcon’s treatment. But he said the recovery time from surgery for such an injury is at least three months. He said it is possible, through surgery, for toe function to be restored fully.

If the ligament is torn and unstable, Kwong said, “it’s more likely than not that you’re going to have to repair it in a high-performance athlete.”

The plantar plate is described as a ligament structure at the bottom of the foot. In an injury such as Garcon’s, that ligament structure has become insufficient, such as through tearing, and the toe lacks stability. Kwong said the injury can occur either through wear and tear, or via a single incident.

“It can happen in both ways,” Kwong said. “I couldn’t say which is more often. You could have a non-athlete, for instance, who steps in a divot and the toe bends back too much. Or it could be a chronic thing.”

The second toe is most often affected, Kwong said, because of the way forces affect the foot while it is in use.

“It’s more of a sore, nagging injury,” Kwong said. “It doesn’t allow you to push off and do what you need to do as far as propulsion and stopping ability.”

Garcon has said he has been told the injury is not common for football players. But the Dallas Cowboys placed linebacker Sean Lee on the season-ending injured reserve list last month. Lee declined to comment about his ailment through a Cowboys spokesman, but he reportedly suffered a similar injury to the big toe on his right foot and underwent surgery.

Fellow Redskins wideout Josh Morgan has played with a turf-toe injury, so he readily can empathize with Garcon.

“I can definitely relate,” Morgan said. “It makes your plants not as sharp. It makes your routes not as sharp. It makes you not accelerate as much as you can. It frustrates you because it’s such a physical game and it’s so hard, and you just want to be at your best. The game is fast and everybody is good, so you want to be at your best out there.”

When Garcon returned to practice Monday, Morgan said he could see how much it meant to his teammate.

“The smile on his face when he was going out there Monday, that just said it all,” Morgan said, standing in the middle of the team’s locker room at midweek. “That’s sports. That’s what we do this for. People really love to play this game. It kills us when we can’t do something right. . . . When you really love the game, it’s in your heart. You can see. He’s still over there smiling.”

Redskins notes: Shanahan said right tackle Jammal Brown, who is attempting to come back from preseason hip surgery, did not practice Thursday because his hip was sore.

Brown remains on the physically unable to perform list and is being evaluated so the team can decide whether to activate him or place him on the injured reserved list.

Thursday’s practice would have represented Brown’s first practice in pads.

“It was a setback, but we’ll find out shortly how bad it is,” Shanahan said.

Mike Jones contributed to this report.