BOSTON — With the Red Sox leading, 4-2, entering the top of the ninth inning Saturday, the bullpen doors swung open and the closer ran onto the field.

Except that closer wasn’t Aroldis Chapman, the usual suspect. It was Greg Weissert, on for a chance at his third career save with Paul Goldschmidt, Jazz Chisholm Jr. and Anthony Volpe due up.

It wasn’t that manager Alex Cora liked the right-handed Weissert over the left-handed Chapman in that spot. Cora acknowledged after the game that Chapman, who had pitched five times in the last seven days, was unavailable no matter the situation.

“Chappy was down,” Cora said.

Chapman pitched the final two games in New York over the weekend, saving both games, then went for a third straight day in the 10th inning of Monday’s loss to the Rays. He didn’t pitch Tuesday (Weissert got the save in that one) but closed out Wednesday’s win, then threw 14 pitches Friday. That was likely his limit entering Saturday.

Weissert, who has emerged as Cora’s preferred setup option alongside Garrett Whitlock with Justin Slaten sidelined, didn’t get the save without some drama. Goldschmidt led off with a Green Monster double, then scored on back-to-back ground balls to second base that allowed him to take third, then home. Things got really dicey when Jasson Domínguez hit an opposite-field two-bagger that put the tying run on second base. But Weissert got Austin Wells to fly out to the center field warning track on a ball that left the bat at 106.1 mph and traveled 365 feet.

“Goldschmidt hit a fly ball to left. It hit the wall,” Cora said. “Domínguez hit a flare and then Wells crushed that one, but not tonight. The conditions were tough out there and the ball stayed in the ballpark.”

Weissert entered the night with a 1.69 ERA (4 earned runs in 21 ⅓ innings) and 20 strikeouts in 23 appearances since April 22. The Goldschmidt run was only the third he has allowed in 15 appearances since May 16.

“With Slaten down, he has done an amazing job,” Cora said. “