Ike Davis better hope what happens in Vegas doesn’t stay in Vegas, because that is exactly where he is heading. It finally became too much for even the general manager to watch. With his team bumbling through two straight extra-inning losses to arguably the worst team in baseball, Sandy Alderson had to make a change Sunday. After the Mets lost to the Marlins, 8-4, in 10 innings at Citi Field, Alderson sent struggling first baseman Davis, reliever Rob Carson and outfielder Mike Baxter to Triple-A Las Vegas. “It’s tough to sit through 30 innings and score not even a handful of runs,” Alderson said. “So it’s been frustrating for everybody. I am sure it’s been frustrating for our fans, too. “We’ve got an off day tomorrow and we gotta pick it up on Tuesday.” On Tuesday, it will be a different-looking Mets team that tries to turn things around against the Cardinals at Citi Field with first baseman Josh Satin, outfielder Collin Cowgill and lefty Josh Edgin heading to New York. The news, which left the clubhouse hushed and shocked, was a dramatic end to a rather brutal weekend for the Mets (23-35), who on Saturday dropped a 20-inning game to the Marlins (18-44), owners of the worst record in baseball. Of the Marlins’ 18 wins this season, eight have come over the Mets. Sunday was a low point of his three seasons here, Terry Collins said after watching his team make fundamental mistakes, base-running mistakes and take just awful at-bats. He addressed his players after the game and told them that they had earned the right to get to the major leagues, but not necessarily to stay here.