Redskins outside linebacker Trent Murphy had a career season in 2016. (Toni L. Sandys/The Washington Post)

INDIANAPOLIS — Washington Redskins outside linebacker Trent Murphy is facing a four-game suspension for violating the NFL’s policy on performance-enhancement drugs, according to multiple people with knowledge of the situation. The suspension is currently being appealed by Murphy. If upheld, he would miss the first four games of the 2017 NFL season.

Redskins senior vice president of communications Tony Wyllie declined comment Sunday evening and deferred to the NFL and the NFL Players Association. The NFL also declined and the players’ union did not respond to an email request.

Murphy, 26, had a breakout season in 2016, recording a career-high nine sacks and three forced fumbles in 16 games, as part of a three-man pass rushing rotation for Washington with Ryan Kerrigan and Preston Smith. He had recorded six sacks and three forced fumbles in 31 games during his first two seasons with the Redskins.

Selected in the second round out of Stanford in 2014 during a draft in which the Redskins did not have a first round pick, Murphy hadn’t lived up to expectations during the start of his career as an outside linebacker. He was effective against the run but struggled as a pass rusher, finishing with just 3.5 sacks in 14 starts during the 2015 season.

The Redskins decided to switch him to defensive end at the start of last offseason ahead of his third season. Murphy gained nearly 30 pounds as part of the adjustment to his new role during offseason practices. The team lacked depth at outside linebacker, however, after Junior Galette tore his Achilles’ tendon for the second straight year and was placed on the non-football injury list before the team reported to Richmond. With a roster relying mainly on Kerrigan and Smith at the position, the Redskins decided to switch Murphy back to outside linebacker during training camp.

It forced Murphy to cut the weight he had gained in anticipation of playing defensive end, but he was still able to produce his most productive season in the NFL under then-position coach Greg Manusky, who was promoted to defensive coordinator this offseason.

Murphy’s possible suspension is just one of many questions the Redskins have at outside linebacker heading into free agency, which begins Thursday, and the NFL draft next month. Smith has flashed his potential over the last two seasons, but he has lacked the consistency the Redskins need out of him. The Redskins also restructured Galette’s contract to bring him back on a one-year deal worth up to $800,000, with a $775,000 base salary, but he has yet to play a down for the Redskins since he signed in 2015.

“Junior obviously has great energy and great confidence in his ability, he just hasn’t been able to display that the last couple of years with his injuries,” Coach Jay Gruden said Wednesday when he spoke to reporters at the NFL combine. “[We] counted on Junior the last two years and unfortunately he popped his Achilles. It really hurt our feelings, and it hurt his feelings. We get him back for another year. He’s going to work, he’s going to practice hard, he’s going to play hard but we’ve got to get him healthy. But he’s going to give us a big boost if he can play.”

Washington could be looking for a pass rusher in the draft as it attempts to improve the talent on defense this offseason. It has been intrigued by a few pass rushers in this year’s draft and met with Kansas State defensive end Jordan Willis and Villanova defensive end Tanoh Kpassagnon. Both players have made strong impressions at the Senior Bowl and the NFL combine to improve their draft stock heading into college pro days this month.