Washington Redskins cornerback Phillip Buchanon returned to the practice field Tuesday, two days after his four-game suspension for violating the league’s substance abuse policy ended. And Coach Mike Shanahan said the 10th-year veteran could play as early as Oct. 16, when the Redskins return from the bye week to host Philadelphia.

For now, the Redskins still are carrying all three backup cornerbacks, Kevin Barnes, Byron Westbrook and rookie Brandyn Thompson, but will have to decide whether to cut one of them or a player at another position to make room for Buchanon on the 53-man roster. Washington was granted a roster exemption, which will expire Monday, so they don’t have to make a move until then. But, if the team decides to activate Buchanon before Monday, they have to release a player at that time.

Buchanon injured his right shoulder during the preseason, but said after Tuesday’s practice that he felt “pretty good,” and hopes to be able to help the Redskins soon.

“I’m just going to take it day-by-day, going to be in the training room pretty much this whole week,” said Buchanon, who last season started five of 16 games and recorded 49 tackles and two interceptions. “I just want to help this team. We’re 3-1 right now and that’s a good feeling. Unfortunately for me, I wasn’t able to be a part of the first four, but I look forward to being part of the next 12.”

Buchanon, who re-signed with the Redskins as a free agent this summer, declined to discuss the specifics of what earned him the suspension.

“I don’t want to talk about it,” he said. “It was an honest mistake. Things happen, so I just put it in God’s hands and I look forward to making plays.”

Buchanon said he didn’t know what his coaches’ plans were for him, but Shanahan indicated following Tuesday’s practice that Buchanon will be worked in immediately.

“He’s working out today. Of course when he left he was a little bit sore with that shoulder. And that looked pretty good today,” Shanahan said. “I’m going to find out from the NFL exactly when we do have to make a decision to let a player go, and when we do, we’ll make that move. But [Buchanon is] going to help us right away. He can help our football team. I’ve got to check out here in the next couple weeks what type of shape he’s in. Hopefully he can help us against Philly.”

Buchanon said he believes, if given the green light, he can help the Redskins right away. And fellow defensive back DeAngelo Hall said that he too is confident that Buchanon can slide right in and boost Washington’s secondary.

“Absolutely. He’s a veteran guy and has made a lot of plays for us last year, and he’s a guy who knows what’s going on, veteran guy, starter in this league,” Hall said. “To get him back is definitely going to add depth. To have him back is going to have [Barnes] scrambling, a lot of other guys scrambling to keep their positions.”

Barnes, the third-year Maryland product, has served as the team’s third cornerback, meaning he has played most extensively of any of the backup defensive backs. Westbrook has contributed both on defense and on special teams. And Thompson has appeared in two games and recorded two tackles, but still is eligible to be placed on the team’s eight-man practice squad.

But, the Redskins defensive coaches are high on Thompson and instead could choose to part ways with a seldom-used player at another position.