ASHBURN, Va. — For the second straight year, the Washington Redskins’ first-round draft pick will have his season cut short because of injury.

Rookie defensive end Jonathan Allen is expected to miss the rest of the season with a Lisfranc sprain, according to multiple people with knowledge of the situation Wednesday. Allen, suffered the injury during the second half of Sunday’s 26-24 victory over the San Francisco 49ers at FedEx Field.

Allen left the locker room in a walking boot, and Redskins coach Jay Gruden hoped the defensive lineman would be sidelined for just three to four weeks. His optimism was voiced before Allen received further evaluation by Dr. Robert Anderson, however. It was after that examination the timeline was extended.

Allen has been a vital piece along the defensive line and quickly made an impact in his first season, particularly with his interior pressure in the nickel package. Through five games, Allen had three sacks, two hits and eight hurries, according to Pro Football Focus. Those totals have been roughly twice as good as an average NFL defensive lineman. Allen was also part of a defense ranked eighth against the run, allowing just 88 yards per contest.

“He is a young player, but he plays it like a veteran,” Gruden said on Monday. “He has got great fundamentals. He’s got a great idea of run/pass, how to get off blocks. He has got strong hands and he was getting a pretty consistent pass rush push. He doesn’t have a lot of sacks obviously, but he was getting push in the pocket which was critical for the interior guys so the edge guys can get home. Just all around, he has played well.”

With the injury to Allen, the 17th overall pick this year, Washington has had its last two first round picks play just seven games in their rookie seasons. Wide receiver Josh Doctson, the team’s 2016 first round pick, dressed for two games last year and was eventually placed on injured reserve because of a lingering Achilles’ injury.

Allen, 22, was considered by some as the best defensive line prospect in the draft. While many draft analysts predicted the Alabama product would be a top-five pick, Allen slid to the Redskins because of mild arthritis in both of his shoulders, which each have been surgically repaired.

Under defensive line coach Jim Tomsula, Allen started all five games but was part of a four-man rotation at defensive end. He averaged 32.5 snaps per game through the first four contests and received 29 snaps against the 49ers before the injury.

The Redskins will continue to rely on Matt Ioannidis, Stacy McGee and Terrell McClain at the position, but second-year lineman Anthony Lanier will receive an opportunity to contribute. Lanier, 24, fought his way on the 53-man roster as an undrafted rookie out of Alabama A&M last year and appeared in four games. Lanier has been the team’s fifth defensive end, but he has been inactive for the first five games.

MOVES: The Redskins put kicker Dustin Hopkins on injured reserve with a strained hip muscle and signed free agent Nick Rose to replace him. The team announced the moves Wednesday. Rose’s NFL debut will come Monday night in Washington’s game at the NFC East-leading Philadelphia Eagles.

The Associated Press contributed to this article.