The Washington Redskins have restructured center Will Montgomery’s contract to gain salary cap space.

The team guaranteed a portion of Montgomery’s contract so the money could be prorated over the entire length of the deal for salary cap accounting purposes, freeing $2 million in immediate cap space, a person familiar with the situation said.

The Redskins lost at least $18 million in salary cap room for this year in a penalty imposed by the NFL Monday. The league ruled that the Redskins structured player contracts improperly in 2010, when the sport had no salary cap, to gain an unfair advantage over other teams in subsequent seasons, when the salary cap went back into effect.

The league cut $36 million from the Redskins’ salary cap over a two-year period. The team must absorb at least half the reduction this season, people with knowledge of the case said earlier this week. The league reduced the Dallas Cowboys’ salary cap by $10 million over a two-year span for similar reasons.

Both teams have denied wrongdoing.

Redskins officials declined to say Friday whether the team will contest the league’s decision. A person familiar with the case said Thursday that the Cowboys are unlikely to challenge the ruling.

More on the salary cap cut:

Redskins must take half the hit this year

Jenkins: It’s Snyder’s fault

Hamilton: Punishment but no crime