Kirk Cousins has said all the right things about the Washington Redskins’ latest quarterback controversy. And although Cousins maintains he’s only a place-holder for Robert Griffin III, he clearly enjoys his new standing atop the depth chart.

Even if Griffin does not return this season from a dislocated ankle, Cousins may not remain there if his turnover problems continue. He failed miserably Thursday night in that key area, committing five turnovers in the New York Giants’ 45-14 blowout victory.

Four days after his stirring 427-yard performance in a road loss to the NFC East rival Philadelphia Eagles, Cousins had four interceptions and lost a fumble in another game within the division. In a laugher that was all but over as the Giants held a 17-point halftime lead, Cousins rarely appeared as effective as he did while directing an offense that generated 500-plus yards in the close shootout at Philadelphia.

Cousins’s four second-half interceptions played a big part in the crowd’s early exodus from FedEx Field. As poorly as Cousins played in being booed, Redskins fans had a lot about which to complain.

Giants quarterback Eli Manning torched Washington’s secondary, which figures to be in big trouble the remainder of the season without top cornerback DeAngelo Hall. Giants tight end Larry Donnell looked like a future Hall of Famer.

The Post's Gene Wang and Scott Allen break down the Giants’ 45-14 rout of the Redskins. Kirk Cousins was responsible for four interceptions and a fumble after being sacked, while Eli Manning led a balanced attack and threw for four touchdowns while also rushing for one himself. (Randolph Smith/The Washington Post)

Dominated from start to finish, the Redskins have a lot of work to do. They took a big step backward at quarterback. That’s a good place to start.

Missed opportunity

With another strong outing Thursday, Cousins could have continued to build a strong case to eventually unseat Griffin as the Redskins’ franchise quarterback. To say the least, that didn’t happen.

The most disturbing aspect of Cousins’s performance? How his four interceptions occurred. To put it bluntly, sometimes Cousins is too decisive. On four occasions after halftime, he targeted receivers and didn’t throw elsewhere even though the Giants’ coverage dictated he should have. It’s a major flaw in his game.

He gift-wrapped passes for cornerbacks Prince Amukamara and Trumaine McBride and safeties Quintin Demps and Antrel Rolle. The Giants’ defensive backs didn’t make great plays. They were where they were supposed to be, and Cousins put the ball in their hands.

Usually, Cousins is efficient at redirecting defensive backs with pump-fakes and motioning his body in different directions. When Cousins throws interceptions, he seems to forget everything he knows about the art of playing the position.

Cousins has played in 10 games. He has 13 interceptions and five fumbles, of which opponents have recovered three. You can’t average 1.6 turnovers a game and start at quarterback in this league for a successful team. That won’t work.

For Coach Jay Gruden, Cousins is an intriguing long-term option to lead the offense. But no matter how much promise Cousins shows, Gruden doesn’t want a turnover machine at quarterback.

Cover that guy

Listed at 6 feet 6, 265 pounds, Giants second-year tight end Larry Donnell is hard to miss. And Donnell entered Thursday’s game with 10 receptions for 182 yards and a touchdown. The Redskins realized Donnell could hurt them. It didn’t seem like it, though.

From the start, the Redskins’ coverage on Donnell was awful. It didn’t improve.

Linebacker Perry Riley Jr. was not quick enough to keep pace with Donnell. Safety Brandon Meriweather played too loose against him. Rookie cornerback Bashaud Breeland gave up too much size. The result? Manning and Donnell connected on three first-half touchdown passes. Riley had the worst experience.

On the Giants’ second possession of the game, Manning and Donnell went at Riley. On third and two from the Washington 16-yard line, Donnell separated from Riley and gained five yards. With Riley in coverage three plays later, Manning threw quickly to Donnell for a five-yard touchdown toward the back of the end zone. They were only getting warmed up.

In the second quarter, Donnell beat Meriweather off the line and scored easily on a six-yard touchdown. Meriweather gave Donnell a ridiculously big cushion and wasn’t quick enough backpedaling. That’s a bad combination. The third Donnell-Manning touchdown of the half was about as good as it gets in red-zone passing.

Split out wide right, Donnell was isolated against Breeland, making his first NFL start in place of Hall. Donnell made a nifty shoulder fake, getting Breeland a little off-balanced as he got off the line without being jammed. Breeland played the corner fade route about as well as it could be played, but he’s listed at 5-11. Manning put the ball high, and Donnell easily out-jumped Breeland for a six-yard score.

Donnell, who does many things well, appears to be a good player. Against the Redskins, he looked like an emerging superstar.

Missing DeAngelo

Hall’s season-ending Achilles’ tendon injury opened another huge hole in Washington’s already porous secondary. The 11-year veteran is the Redskins’ captain on defense and one of their emotional leaders. More importantly, Hall is the linchpin to the team’s coverage.

Defensive coordinator Jim Haslett relied on Hall. In game planning, Haslett would devise alignments based on Hall’s ability to cover the best wide receivers on other teams.

It’s not surprising Haslett would lean on Hall. Most play-callers essentially form partnerships with top players. But Hall was the Redskins’ only proven play-maker in the secondary. When most of your other players on a unit are below average, the top guy becomes even more important.

Second-year cornerback David Amerson isn’t ready for the role he now must fill. His growing pains showed on the Giants’ third touchdown drive of the first half.

On second and nine from the New York 45-yard line, Amerson lined up wide left against wide receiver Rueben Randle. A step behind Randle as they raced down the sideline, Amerson turned his head late, locating the ball after it landed in Randle’s hands for a 27-yard gain. The drive ended on Donnell’s scoring catch over Breeland. Hall is among the best in the league at locating the ball in the air. Sounds simple? It’s not. Just ask Amerson.

In the opening half, Manning had only four incompletions in 24 attempts. He passed for 209 yards and three touchdowns.

Overall, Manning finished with 300 yards, four touchdowns and one interception. He made it look easy, and the Redskins’ secondary helped.

The takeaway

There’s no doubt Cousins is more comfortable in the pocket than Griffin. He’s also better suited to run Gruden’s offense, which is predicated on timing and rhythm. Cousins is a rhythm passer — but he never got in a good one against the Giants (2-2).

At 1-3, the Redskins will be coming off a horrendous performance when they host the Seattle Seahawks in Week 5. Facing the defending Super Bowl champion is not an ideal situation for a team that’s worried about the psyche of its starting quarterback and attempting to patch together a bad secondary that is even worse than when the season began. Gruden always wanted to be a head coach. Well, the honeymoon is over. Time to get the job done.

For more by Jason Reid, visit washingtonpost.com/reid.