ASHBURN — There was a time when Spencer Long was ticketed for the starting right guard position on the Washington Redskins‘ offensive line, back in the dog days of training camp, after the team released Chris Chester in June.

Without Chester, who started at right guard the last four seasons, Long played the position next to rookie Brandon Scherff, then playing right tackle.

That pairing produced mixed results. At the same time, second-year tackle Morgan Moses was finally healthy after sustaining a Lisfranc sprain in his left foot, which ended his season last December. The Redskins plugged Moses in at right tackle and slid Scherff, the team’s No. 5 overall pick in the draft, to guard, which pushed Long on the bench.

“I was not a very happy camper,” Long said on Wednesday. “But, you know, it was kind of a learning lesson for me to really practice what I preach and focus on what I can control. Just, how can I, Spencer Long, get better every day, you know what I mean? I really had to buckle down and not worry about the extra [B.S.] and just keep grinding, and it really forced me to actually do that.”

Now, Long’s focus is on keeping quarterback Kirk Cousins upright and clearing rushing lanes for the Redskins on Sunday when they host the Philadelphia Eagles at FedEx Field.

The Redskins placed left guard Shawn Lauvao on injured reserve on Tuesday after he sustained a lateral sprain in his left ankle during the team’s 32-21 loss to the New York Giants last Thursday.

After the game, coach Jay Gruden said he expected Lauvao to “miss some time.” The severity of the injury was revealed on Wednesday, when Gruden said Lauvao needed surgery to repair ligaments and tendons in the ankle.

Without Lauvao out, the Redskins expect Long, a second-year guard, to fill the void on the left side.

Gruden said Long and rookie Arie Kouandjio, who were both inactive the first three games, are competing for the open spot, though he added Long has the advantage. On Wednesday and Thursday, Long took reps with the first-team offense.

A third-round draft pick out of Nebraska in 2014, Long played in five games last season, mostly on special teams, totaling 16 snaps on offense. In his senior year as a right guard with the Cornhuskers, he played only six games after tearing the MCL in his left knee.

“Spencer has had to work on everything,” Gruden said on Wednesday. “When we got him out of Nebraska, he didn’t play his senior year that much. Coach [Bill] Callahan has been grinding him on everything — pass protections, footwork, his pad level, everything, passing off stunts. He’s doing better and better.

“Brandon [Scherff] was playing well at right guard. Shawn [Lauvao] was too, but now [Long]’s got a golden opportunity. We don’t have any problems with Spencer Long in the lineup. That’s for sure. We feel very good about him playing. He’s done a good job.”

Losing Lauvao is a big blow to the Redskins‘ offensive line, which has excelled in the first three games of the season. Quarterback Kirk Cousins has been sacked just four times — tied with the Atlanta Falcons for ninth-least in the NFL.

More importantly, the Redskins pulled Lauvao frequently in their zone-blocking run game. The Redskins have rushed for 431 yards this season — fourth-best in the NFL.

Long, now thrust into a starting role, will benefit from playing in between two veterans in left tackle Trent Williams and center Kory Lichtensteiger, as he battles Philadelphia’s defensive line.

“[Kory] is our most valuable player on offense,” Gruden said. “He does a great job of keeping everybody intact, getting to the right people, making the communication calls, protection calls, all the different calls that we have in the run game.

“He’s done an excellent job, so we’re leaning heavily on Kory to help the two young guards. Trent will do a great job with Spencer or Arie, whoever the left guard is. Those two guys are our leaders on the offensive side of the ball and they’ve done a good job. I expect that to continue.”

Lichtensteiger said it will be a tough adjustment playing without Lauvao, but is confident in the Redskins‘ depth on the offensive line. Williams was not concerned, either.

Long has not dressed in a game this season, but Williams sees the effort the line puts forth in practice to learn the calls and protections, regardless of who is in the lineup.

Williams said he will be there for Long when he needs a tip, but doesn’t anticipate that happening too often.

“If I can tell he’s confused over a look, if I know what’s going on, I can give him a quick hint before the play starts,” Williams said. “Guys are going to have to be their for their own sake, you’ve got to know the look, but we don’t worry about it because we know how hard we work and how diligent we’ve been in this process.

“We don’t have many missed assignments, but that comes from the top. They’re tough on us and guys have reacted in a positive way. I think Spence is going to do a great job.”