BOSTON -- The task of catching up in the standings was already looming as a hard one for the Red Sox. But it got even tougher about an hour before Tuesday’s 9-7 loss to the Braves in 11 innings at Fenway Park, with the news that closer Tanner Houck was placed on the injured list with lower back inflammation.

For weeks, the mantra for the Red Sox has been about having players due to return from the injured list to fortify their roster for the final stretch.

But as they wait for Michael Wacha, Kiké Hernández, Trevor Story and more to return, other health problems continue to mount.

• Latest news and injury updates for the Red Sox

There was unfortunate news before the Sox even got to the ballpark on Tuesday, when the club announced that Chris Sale was in a bike accident on Saturday and broke his right wrist. His season is over. Sale was already recovering from a fractured left pinkie finger, an injury sustained in his second start back from a fractured right rib cage.

And now, there’s the loss of Houck from the bullpen, the area that has been Boston’s weakness for most of the season.

“It’s going to be tough, but guys have to step up,” said Red Sox manager Alex Cora.

The Red Sox saw just how daunting that task will be on Tuesday, when the bullpen gave up five runs (three earned) on six hits and six walks while striking out only four in seven innings.

At 54-57, Boston is five games out of the third American League Wild Card spot. And now, Cora’s team will need to beat a string of tough opponents (the Braves, the Orioles and the Yankees) over the rest of this homestand without its most important reliever.

Tuesday’s blown save by Matt Barnes was the 23rd of the season by Boston, the second most in MLB. The bullpen has a 4.41 ERA, which ranks 26th in the Majors.

It makes a shaky start like the one Rich Hill had (four innings with four runs allowed on seven hits) more magnified.

“Yeah, I was terrible,” said Hill. “I have a lot of other words for it. It starts with me and not giving the bullpen a chance. We had to go to the bullpen early. I couldn’t get through five innings. That doesn’t sit well with me.”

The earliest Houck can pitch again for the Sox is on Aug. 21, as his move to the injured list was retroactive to Saturday. But it’s far from certain he can make it back that fast.

“Heartbreaking,” Houck said of the injury. “Any time you go on an IL stint, it’s going to be heartbreaking, no matter what. You want to be out there competing with the guys every single day. Just counting the days until I’ll hopefully be back.”

When might that be?

“We’ll know more [Wednesday], “ said Cora. “He’s been dealing with it for a while. That’s why we tried to stay away whenever we could [from Houck recently]. That’s why you saw [Garrett Whitlock] going three, John [Schreiber] going multiple innings, just to see if he was feeling better. He actually felt better in Kansas City, but now we have this.”

The best-case scenario is the one Houck is rooting for. Boston’s postseason hopes, already waning, could depend on Houck needing just the minimum time required by his IL stint.

“I hope it does wonders. Time heals everything,” said Houck. “Hopefully, with a little bit of rest, recovery and our incredible [training] staff, [I’ll] get back on the field as soon as possible.”

Schreiber, Whitlock, Ryan Brasier, Barnes, Hirokazu Sawamura and Austin Davis are among the pitchers Cora will have to lean on more while Houck is out.

It sure didn’t take long for the loss of Houck to seem glaring. While Whitlock got the Sox through a scoreless ninth after a mishap in the eighth, Cora had to turn to righty Kaleb Ort in extras.

Ort was the depth righty who was called up to take Houck’s spot on the roster on Tuesday. The difference in the two teams’ relief situations was evident, as the defending World Series champion Braves called on one standout reliever after another in the late innings.

“It’s unfortunate how it ended,” said Houck. “I have full faith in all those guys out there. I know how hard they work, so [I] continue to root for them and just do my part whenever I can.”