The Washington Redskins on Friday named rookie Dwayne Haskins their starting quarterback for Sunday’s game at Buffalo, giving the first-round draft pick his first opportunity to start.

Interim coach Bill Callahan, who announced the move after practice, had hoped not to start Haskins because he wanted to give him more time to develop. But starting quarterback Case Keenum remains in the NFL’s concussion protocol, still recovering from an injury he suffered Oct. 24 in a loss at Minnesota, and is ineligible to play.

Colt McCoy will back up Haskins. Callahan has said he wants to keep McCoy as an emergency reserve and not use him as a starter.

Haskins has struggled in his first NFL season, completing 12 of 22 passes for 140 yards with no touchdowns and four interceptions in parts of two games. His quarterback rating is 34.5 on a scale of 0 to 158.3. His lack of early success has been a topic of much discussion; several people with knowledge of the team said this past week that he has struggled to know the playbook.

Haskins, 22, played only one full season at Ohio State, throwing 50 touchdown passes and only eight interceptions before being drafted by the Redskins with the 15th pick in April.

Redskins coaches said Friday that Haskins had practiced well during the week, working with the first-team offense while Keenum sat out.

“We have seen him progress through the week, and I think that’s the big thing, his improvement from day to day, from situation to situation, from drill to drill. He’s been nothing but locked and focused,” Callahan said.

In the two games Haskins has played — a loss to the New York Giants on Sept. 29 and the defeat at the Vikings — he has had trouble getting the plays called and gathering the players together. A lot of that, coaches said, is inexperience because he started only 14 games at Ohio State and didn’t do much work with the Redskins’ first-team offense in training camp or during the season’s opening weeks.

Anticipating that Haskins might start this week, Redskins coaches spent a lot of time focusing on reducing the time it takes for Haskins to get the ball snapped. They set the scoreboard clock to 40 seconds, 35 seconds and 25 seconds to create frantic scenarios in which the play had to be rushed in, Haskins had to deliver it to the rest of the offense and get everyone set and the ball had to be snapped.

“I think it’s important that he knows that he’s the starter and that he goes out there with the mind-set that he’s the leader of this offense,” Callahan said. “I know that he’s going to accept that responsibility and do as well as he can.”

Haskins has not had the luxury of entering an ideal situation, the way some other young quarterbacks have. The Redskins are going through a dysfunctional season. They are 1-7. They fired coach Jay Gruden in October and are battling with star left tackle Trent Williams, who ended a five-month holdout this week and then said team doctors failed to properly diagnose a cyst that turned out to be cancerous. There also have been a number of injuries on offense, including the loss of the team’s top two tight ends, Jordan Reed and Vernon Davis, to concussions.

Callahan and offensive coordinator Kevin O’Connell said Haskins has become more focused and serious since he made his debut against the Giants. They described a player who was realizing how important his job has become and said he has spent considerably more time in the team’s headquarters and meeting rooms, studying and asking questions.

“His focus has been even more sharp the way he’s preparing,” said Redskins wide receiver Terry McLaurin, who was Haskins’s teammate at Ohio State. “He’s really been focusing on preparing like he’s a starter. Now he’s in a situation where he’s getting all the reps this week. I’m looking forward to seeing how his development is from just last week to this week. He’s the ultimate competitor, but whether he throws a touchdown or has negative plays, it’s the course of the game, so he has to be prepared for anything.”

Haskins did not speak to reporters Friday. When asked Wednesday about the way he has grown as the potential starter, he said: “I don’t think it had nothing to do with this week. I just think it’s a change in me.”

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