Kirk Cousins and the Redskins remain upset after a costly penalty appears to have been incorrectly called during Washington’s final drive in regulation. (Jonathan Newton/The Washington Post)

Jay Gruden’s words were measured and monotone, but his frustration was more than evident.

Less than 24 hours after his team suffered its most crippling loss of the season in gut-wrenching fashion, the Washington Redskins’ head coach still couldn’t explain one of the game’s most controversial plays.

Plenty of factors converged to produce a 34-31 overtime defeat at the hands of Drew Brees and the New Orleans Saints (8-2). But perhaps Sunday’s loss might have been somewhat easier to accept — or might have ended differently — had the referees not called intentional grounding on Redskins quarterback Kirk Cousins on a first-and-10 play from the New Orleans 34-yard line with 31 seconds left in regulation.

“It doesn’t sit very well with me at all,” Gruden said.

The Redskins — who had led by 15 points in the fourth quarter — were hoping to reclaim the lead from the Saints on their final drive and escape with the upset win. But when Cousins, immediately after taking the snap, sailed a pass over wide receiver Jamison Crowder and toward the sideline, the officials threw a flag for intentional grounding, a 10-yard penalty, which pushed the Redskins (4-6) out of field goal range and resulted in a 10-second clock runoff. The controversy stemmed from whether the play fit the NFL’s definition of intentional grounding.

An NFL official suggested to The Washington Post on Monday that the league believes the penalty should not have been called, given the fact the intentional grounding rule requires the passer be “facing an imminent loss of yardage because of pressure from the defense.”

The NFL, however, declined to say whether there was any postgame communication about the call between the Redskins and senior vice president of officiating Al Riveron. But any acknowledgment by the league about the controversial call will be of little comfort to Cousins & Co.

“I can handle non-calls from time to time. But I can’t handle calls that aren’t calls, if that’s the fact,” Gruden said. “You have two receivers in the area [Crowder and Josh Doctson], and he threw it over their heads. I mean, it is perfectly legal for a quarterback to overthrow a receiver; a receiver not to be looking and the ball fly over his head. It happens all the time.

“[Cousins] wasn’t under duress. Maybe I don’t understand the rule. We’ll get clarity on it and if I’m wrong, I’m wrong. A costly mistake. And if I’m right, then it’s too bad.”

The infraction helped to seal their fate, as Cousins was sacked and fumbled on the ensuing play, the final snap of regulation before Brees carved up the Redskins’ defense in overtime.

“The letter to [Redskins President] Bruce Allen or whatever they do to say, ‘We’re sorry, wrong call,’ or whatever it may be, you know, it’s tough,” Cousins said Monday during his weekly appearance on 106.7 the Fan’s Grant and Danny program. “Because nobody will be bringing that up in February or March, when we’re making decisions about which direction to go as an organization.

“You know, that’s the kind of thing that we appreciate the clarification, but it really doesn’t do much. I mean, this is our careers. This is our livelihood. This is what we do. It just is frustrating when a letter is really all you get, when it had such a major impact on the direction of our lives, when we’re in it and doing it every day.”

Cousins explained his intention at the time was to throw a quick incompletion after Gruden saw the Saints’ defensive formation would likely stuff the running play Washington had called. Instead of audibling to a passing play, Cousins instead wanted to kill the play as quickly as possible with an incompletion rather than risk a negative play. He aimed his throw toward the sideline, acknowledging that throwing the ball at Crowder’s cleats “would have been better.” But he still didn’t think his errant throw should have resulted in an intentional grounding call.

“I’m thinking, ‘Well, Crowder and Doctson are over there, if I literally just throw it over their heads, they’re in the area, they’re eligible receivers,” Cousins continued. “Not to mention, if I’m not under pressure it’s not intentional grounding because I’m not really at risk of a sack. So I can just throw it in their general direction, and because I’m not under pressure and because they’re in the area, it won’t matter. And you saw what happened. I threw the ball and it looks like I’m throwing to nobody, but in my opinion — or before I threw the ball, my opinion was he’ll be in the general area.”

Sunday’s loss all but ensured the Redskins are out of the playoff race — unless they somehow manage to win their final six games with a depleted roster, while the rest of the NFC implodes around them. But Gruden and his players don’t have the luxury of time to reflect on what could have been this past weekend. They have to prepare for back-to-back “Thursday Night Football” games against two of their biggest rivals, the New York Giants and the Dallas Cowboys.

The sting of Sunday’s loss to the Saints still lingers, though. And questions about the game’s officiating at its most critical juncture will continue to haunt Washington. Especially Cousins.

“How do you define the difference between an inaccurate pass and intentional grounding?” Cousins asked on air. “Especially when there’s nobody pressuring you in the sense that you’re actually at risk of a sack? . . . That was my struggle.”

Mark Maske contributed to this report.