EAST RUTHERFORD, N.J. — The New York Giants made a rare in-season house cleaning, firing coach Ben McAdoo and general manager Jerry Reese on Monday, less than a year after the team made the playoffs for the first time since 2011, a person familiar with the situation said. The person spoke on condition of anonymity because the team had not made an announcement. Co-owner John Mara planned to hold an afternoon news conference. The dismissals came a day after the Giants lost in Oakland, with quarterback Eli Manning benched and the team dropping to 2-10. The firings cap an injury-marred season highlighted by the loss of catalyst wide receiver Odell Beckham Jr. on Oct. 8. Defensive coordinator Steve Spagnuolo will take over as interim coach for the final four games. He coached the St. Louis Rams from 2009-11. Assistant general manager Kevin Abrams will take over on an interim basis for Reese, who became general manager in 2007 and had two Super Bowl wins on his resume. But the Giants missed the playoffs four times in the last five years, and this year his failure to address offensive line problems played a major role in a horrible season. The moves came less than a week after the 40-year-old McAdoo made one of his biggest mistakes of his short tenure, mishandling the decision to bench Manning, a two-time Super Bowl MVP. Mara was forced to address the matter the following day and said he wished the decision had been dealt with better. McAdoo had a 13-16 record, and his firing is the first mid-season head coaching move by the Giants since Bill Arnsparger was replaced seven games into the 1976 season by John McVay. The 2-10 mark is the Giants’ worst 12-game record since they were 2-10 in 1976, and their worst since the advent of the 16-game schedule in 1978. A team that traces its NFL origins to 1925, the Giants have been an organization that for decades rarely shakes things up until after the season. Coaches get fired, but it’s at the end of a bad run and usually they get an extra season to fix things. The general’s manager’s job has been orderly succession. The late George Young turned the team around in the 1980s and was replaced by Ernie Accorsi, who eventually gave