ASHBURN, Va. — After going 4-12 in his first season as an NFL head coach, Jay Gruden promised to make changes in the Washington Redskins on his staff as well as the roster in 2015.

“The big thing is not making the same mistakes, trying not to,” said Gruden, who said that he would recommend to owner Dan Snyder and general manager Bruce Allen when they meet that embattled defensive coordinator Jim Haslett be retained for a sixth season although the Redskins allowed the second-most points in the NFC, citing the 36 players the Redskins were forced to use on defense because of a plethora of injuries.

“Nobody got the job done this year. We’re 4-12 so we had issues all across the board. … I promise you this will not be the same football team, football staff that we’ll have at the start of next year. Sometimes the best addition to your football team is subtraction.”

Only three of the most-used starters at the 22 positions — defensive end Jarvis Jenkins and safeties Ryan Clark and Brandon Meriweather — will be unrestricted free agents this winter. They likely will be gone, but as Gruden said, plenty of other changes are coming after a sixth last-place finish in the NFC East in seven years.

The biggest question in personnel involves quarterback, where Robert Griffin III started seven games, Kirk Cousins started five and Colt McCoy started four.

McCoy, who began the season as the third-stringer, put up the best numbers but is unsigned for 2015. Griffin, who hasn’t come close to recapturing the form that made him the 2012 Offensive Rookie of the Year, and Cousins, a backup for his three seasons, are under contract.

“There needs to be some clarity at certain spots and quarterback is one of ’em,” Gruden said while acknowledging that it would be difficult to stage a three-man competition at the position during the offseason and training camp. “I anticipate having a competition next year. You’d like to narrow it down to two. I’d like to pick one as soon as I could. However, until that position is earned, you have to have a competition.”

Neither Griffin nor McCoy talked on breakup day, but Cousins took the step of clarifying his casual remark of earlier Monday that seemed along the lines of play me or trade me, saying, “I’m happy here. If I’m the backup for a fourth year in Washington, so be it. I don’t demand anything. … For three years, I’m focused on being better. I got plenty to work on to get better. I do think with another offseason in Jay’s system, I can really take another step forward. I’ve been a great teammate, a great representative of the Redskins and I want to continue to be that.”

Fullback Darrel Young just finished his fifth season in Washington. All but 2012 have included at least 10 defeats.

“We need to get away from the game right now,” Young said. “(14th-year receiver Santana Moss) spoke to the offense the other night and said, ‘At the end of day, you gotta look at yourselves.’ And I think that’s what everyone going to do this offseason: ‘How I can make the situation better for this team?’ We just gotta understand what we’re trying to do. Are we trying to be football players or are we just trying to make money? I’m not pointing fingers, but when you’re 4-12, it’s a problem and we don’t know what it is.”

Defensive end Kedric Golston said that there’s no point in worrying about whether Haslett or his assistants will be fired and how many players won’t be back.

“You can’t worry about what’s going to happen or not going to happen because you have no control over that,” said Golston, who declined to endorse Haslett’s return or his dismissal. “What you can control is yourself and that’s what you should focus on.”

Left tackle Trent Williams, Washington’s only Pro Bowl player, went into Sunday’s loss to Dallas with a banged-up right shoulder. He left the 44-17 defeat in the second half with a badly injured left ankle that he’s concerned could keep him out of the contest in Hawaii.

“It hurts pretty bad,” Williams said. “(This season) has been a pretty wild ride. We’ll learn from this experience. We’ll grow from it. We had a couple wins (the upsets of the NFC East champion Cowboys in Week 9 and Philadelphia in Week 16) that kinda tested the character of this team. We can go back, look at those moments and try to channel that team that played in those particular games every Sunday next year and I think we’d be in a far better place.”

Williams said this year’s breakup day was better than last year’s because there weren’t moving boxes (as there were for then-coach Mike Shanahan and some of his assistants) this time around.

REPORT CARD VS. COWBOYS

–PASSING OFFENSE: B- — Robert Griffin passed for a career-high 336 yards, but receivers DeSean Jackson and Pierre Garcon did all the work on the screens that gained 65 yards and a touchdown and 47 yards, respectively. Griffin didn’t throw a pass farther than 20 yards, was picked off twice by Dallas linebacker Bruce Carter in the red zone on consecutive second half series and was sacked and stripped at his own 5-yard line for a Dallas fourth quarter touchdown.

–RUSHING OFFENSE: C — Alfred Morris last quarter of the season slump continued with just 43 yards on 12 carries. Third-down back Roy Helu ran six times for 42 yards (and also had four catches for 41 yards). Griffin carried six times for just 19 yards. The blockers opened a couple of holes, but nothing like the chasms that Williams cleared for Jackson and Garcon on their long catch-and-runs.

–PASS DEFENSE: D — In the Week 8 upset at Dallas, rookie cornerback Bashaud Breeland kept Cowboys stud receiver Dez Bryant in check and the constant blitzing tormented and injured quarterback Tony Romo. In the rematch, Bryant burned cornerback David Amerson for two early touchdowns, the first on a 65-yard catch-and-run with a screen, the second on a gorgeous reception in the left corner of the end zone. Dallas’ other receiver, Terrance Williams, toasted David Amerson to set up a field goal. Inside linebacker Keenan Robinson had Washington’s only sack in Romo’s 35 drop backs.

–RUSH DEFENSE: D — NFL rushing champion DeMarco Murray danced through the Redskins for a 9-yard touchdown and backup Joseph Randle raced past them for a 65-yard score. Third-stringer lance Dunbar’s 80-yard jaunt to the house was nullified by a penalty. Murray gained 100 yards on 20 carries as the Cowboys totaled 174 yards on 25 runs. Robinson, who had missed the previous three games with a sprained knee, led the tacklers with 10, two more than fellow inside linebacker Perry Riley. Safety Ryan Clark had eight stops in his likely swansong.

–SPECIAL TEAMS: B — Ben Kotwica’s units seemed surprised by Dallas’ onside kick which bounced past Washington’s Trenton Robinson and was recovered by the visitors. Punter Tress Way, who averaged 44 yards gross and 41 yards net in four punts against Dallas, led the NFL with a 47.5-yard gross average in his first season. Kicker Kai Forbath completed his own best season (24 of 27 on field goal tries) with a 25-yarder against the Cowboys.

–COACHING: D — When your team falls behind 27-7 midway through the second quarter at home against the archrival you beat on the road nine weeks earlier, you and your staff aren’t doing a good job. When you say after the game, that you, as the play-caller, got away from the run too soon (again), that your defense’s tackling was as bad as you had seen in a long time and when your special teams aren’t prepared for an onside kick, it’s a bad day. Not to mention the 44-17 loss.