It's hard to believe that five days ago, Ryan Kerrigan was celebrating a sack with his signature HBK pose against the Green Bay Packers. It moved him just 1.5 sacks away from being the franchise leader in the category, and it was almost a guarantee that he would eclipse that mark by the end of this season.

How things have changed since then.

Kerrigan suffered a calf injury shortly after the takedown, forcing him to miss the rest of the Packers game. Interim head coach Bill Callahan ruled him out of Sunday's game against the Philadelphia Eagles the following day, only to announce Friday that Kerrigan was placed on Injured Reserve, ending his season.

With Kerrigan out, rookie Montez Sweat is set to have an increased role off the edge for the rest of the year.

"It's a bright opportunity," Sweat said Friday. "Just got to hold it down for [Kerrigan]."

After taking quarterback Dwayne Haskins Jr. with the 15th overall pick in last year's NFL Draft, the Redskins traded back into the first round to take Sweat with the 26th overall pick. He quickly became an important piece to the defense, playing in 68% of the defensive snaps in the season opener against the Eagles.

Sweat's playing time has been relatively consistent since then -- he's played 61% of all defensive snaps through 13 games -- and he's been productive during his time on the field. He has 40 total tackles, five sacks, a forced fumble and two pass defenses.

According to NFL.com, Sweat ranks 23rd among rookie defensive players in tackles and tied for 12th among linebackers. His sack total is second for his position and tied for sixth overall.

Sweat's numbers across the board are sure to get a bump in the final three games of the year. Callahan compared him to Eagles defensive end Josh Sweat, who he said has grown throughout the year, and believes Montez is having the same kind of maturation.

"There's flashes of that we see in his play," Callahan said. "I think it's just a matter of overall consistency down in and down out, being that factor to put heat on the quarterback."

With 28% fewer snaps, Josh Sweat has fewer sacks (3) and tackles (15) than Montez.

Sweat has had steady production throughout the year, averaging about three tackles per game. He recorded his first-career sack against the Chicago Bears on Monday Night Football as part of a seven-tackle performance Sept. 23.

One of his better games came two weeks ago against the Panthers when he had three tackles and 1.5 sacks, which remains a season-high for him. Sweat said after the game he "just kept it going" as he built momentum.

"I just honed in during the week on the things that they did and took my keys and I ran with them."

Sweat's breakout performance came in the absence of Kerrigan, who was sidelined with a concussion. In the days leading up to that contest, Callahan pointed to Sweat's effort against the Detroit Lions as a sign that things were "starting to come together" for the rookie.

Sweat's final numbers against the Lions didn't pop off the stat sheet -- he a tackle, a sack and a pass defensed -- but there were flashes of his athleticism and burst off the line of scrimmage throughout the afternoon.

"He's a talented, talented player and he just needs more production as we go forward," Callahan said. "I think he's striving towards that every day, and each game we see him get a little better, whether it's setting the edge, making plays on the boot or rushing the passer, making the big third-down play."

Sweat has played on the left and right sides of the defense throughout the season, and Callahan said that shouldn't change against the Eagles.

"It's different if you were in the 4-3 and you were specifically just a left end or a right end," Callahan said. "But in the 3-4 those guys have a lot of flexibility in terms of going from side to side."

One of the other responsibilities Sweat has in the Redskins' 3-4 defense is pass coverage, which Callahan said also plays a factor in his growth process.

"It's different if you had your hand in the dirt on every down and you're triggered to go the edge whereas he has multiple assignments," Callahan said.

It also helps that with a 6-foot-6, 262-pound frame, Sweat has a unique length advantage over many offensive linemen. That's one of the many things defensive coordinator Greg Manusky likes about him.

"When he uses [his length], good things happen," Manusky said. "He did try to use it [against the Panthers], so I'm happy that he did."

While playing on the left and right sides of the defense have schematically similar responsibilities, Sweat said there are some differences between the two.

"It's like moving from left tackle to right tackle or moving from left cornerback to right cornerback," Sweat said. "It's just different."

Sweat doesn't have a preference, though. He just want to go out and help the defense. That's all that really matters to him.

He'll be doing a lot more of that for the rest of the season.

"I just play within the defense," Sweat said. "Whatever they ask me to do, I do."