Mets catcher Travis d'Arnaud walks back to the dugout after...

Mets catcher Travis d'Arnaud walks back to the dugout after he strikes out looking against the Twins during the second inning in a game at Citi Field on April 9, 2019. Credit: Kathleen Malone-Van Dyke

“Game of Thrones” was supposed to be the theme at Citi Field on Saturday night when the team gave away a Noah Syndergaard bobblehead based on the popular HBO show.

It turns out “Survivor” was the more appropriate theme.

Mets fans voted Travis d’Arnaud off the island with an emphatic series of boos during the Mets’ 8-6 loss to the Brewers. That the stadium was nearly full because of the bobblehead giveaway only amplified the fans’ disgust with the team’s backup catcher.

Brodie Van Wagenen heard you, Mets fans. In a Sunday morning surprise, the Mets fired d’Arnaud — designated for assignment is the official, polite term — and promoted Tomas Nido to back up Wilson Ramos.

“It’s not a knee-jerk [reaction] to any particular play or any particular game,” Van Wagenen said. “But we have to evaluate in real time the different scenarios that take place and what gives us a chance to be at our best.”

Or it’s exactly a knee-jerk (reaction). D’Arnaud not only looked like less than a major-leaguer at the plate but struggled behind it, too. With the Mets’ vaunted starting rotation off to a troublesome start after Syndergaard’s loss on his bobblehead night, Van Wagenen probably wanted to fire someone.

Can’t fire the manager (yet). Can’t fire the pitching coach. Can’t fire the pitchers. So the backup catcher whom the fans can’t stand anyway can be the sacrificial lamb.

D’Arnaud was batting .087 (2-for-23) in sporadic playing time after missing most of 2018 following Tommy John surgery. He’s never been a defense-first catcher, and that’s what the Mets want in Nido, who had better be a great defender. Going into Sunday, he had a .170 batting average in 101 major-league at-bats.

And whaddya know .  .  . Nido smacked a pinch-hit, two-run double to right in the eighth inning in the Mets’ 5-2 win over the Brewers. Initial grade on the transaction: A-plus.

D’Arnaud looked awful Saturday night and committed several baseball sins. He had a passed ball and threw a ball into center on a steal attempt. He was booed before he stepped to the plate in the seventh, then again after he was thrown out at second trying to stretch a single to left with the Mets trailing by four runs.

Later in the inning, Pete Alonso hit a three-run homer. Oops.

It’s just another example of d’Arnaud winning the award for bad timing. He had Tommy John surgery in April of last year, meaning it was going to be difficult for him to be ready for Opening Day this season (throwing is kind of important for catchers).

Van Wagenen made what probably was a rookie mistake when he tendered d’Arnaud a contract in the offseason, which ultimately became a $3.515 million salary. The Mets aren’t usually known for overpaying, but this was a head-scratcher at the time.

Rookie mistake No. 2 was not releasing d’Arnaud during spring training when the Mets could have saved five-sixths of that $3.515 million. The Mets left him behind in Florida but called him up April 7 after two minor-league rehab games.

Whether d’Arnaud can catch on with another team and fulfill his promise at age 30 is questionable, but catching is a position of need on most teams, so he should get another shot.

Back in Flushing, Van Wagenen’s game of “Survivor” will continue, especially if the team struggles and the high-energy GM feels the need to do something other than tweet a picture of the Syndergaard figurine, as he did before Saturday’s game with the opening line “Big night tonight!”

It certainly was for d’Arnaud.

With that in mind, perhaps Mets fans should consider packing Citi Field on Tuesday when Jason Vargas faces the Reds.

If Vargas pitches the way he has for most of his Mets career and the fans boo loudly enough, maybe Van Wagenen will decide to eat what’s left of Vargas’ $8 million salary (and $2 million buyout for 2020). That’s the Mets’ new reality, apparently.

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