BOSTON -- At the end of arguably the worst week a New York Yankees pitching staff ever has gone through, pitching coach Larry Rothschild stood before reporters in the team's clubhouse Saturday evening and took ownership of the poor performances his group has posted in recent days.

"It's my responsibility to get it right," he said.

Rothschild's comments came moments after the Boston Red Sox blasted the Yankees for a third consecutive game at Fenway Park, this one by a 9-5 decision. New York's loss marked the sixth straight game in the rivalry in which Yankees pitching has allowed eight or more runs.

It also marked the seventh game this week in which New York allowed opposing teams to score seven or more runs. After the Colorado Rockies scored eight in a victory at Yankee Stadium last Sunday, the Minnesota Twins scored eight, 12 and seven runs in a series New York actually won. Since Thursday, the Red Sox have beaten the Yankees by plating 19, 10 and nine runs in respective games.

"It's been really tough," Rothschild said. "It's tough on [the pitchers], it's tough on the team."

Mostly, it has been the Yankees' starting pitching that has let them down in recent days. Since June 29, the rotation has posted a 7.09 ERA, the second-worst ERA in the majors across that span. Only the Detroit Tigers' 7.30 mark is worse.

Masahiro Tanaka's 12 earned runs allowed on Thursday -- the second most a Yankees starter ever has given up in a single game -- certainly helped inflate that figure. His individual ERA this season shot up from a 4.00 to a 4.79 following that horrid outing.

Prior to June 29, the day the Yankees beat Boston in a 17-13 offensive explosion in London, the New York starters' ERA was a more respectable 4.13.

Saturday's ineffective pitcher was lefty CC Sabathia, who actually cruised to a 1-2-3 first inning. It was the first time a Yankees starter had a clean opening frame since Tanaka did it last Saturday at home against Colorado.

"Had his slider, had the changeup, had his cutter going early," manager Aaron Boone said of Sabathia.

And then?

"They got some balls on the plate, and that hurt him a little bit," Boone added.

Sabathia gave up a 310-foot solo home run to Andrew Benintendi -- the second shortest non-inside-the-park homer in the majors since 2015 -- with two outs in the second inning, then let three more runs come across in the fourth. Another run chased him from the game in the fifth inning.

"Just didn't make enough pitches," Sabathia said. "That's a good lineup over there, and left too many pitches over the middle."

Sabathia, a noted ground-ball, weak-contact pitcher since developing his cut fastball in 2015, failed to induce a groundout on Saturday. Everything the Red Sox put in play against him was either home runs, fly-ball outs, line drives off the Green Monster or line-drive singles that cleared the infield.

He became the fourth big league starter this season to fail to get a ground-ball out in an outing of at least 4⅓ innings.

"With the stuff I have now, I have to be pitching to the corners," said the 39-year-old Sabathia, whose days as a power pitcher are long behind him. "A lot of balls left middle."

Asked what has been the common thread to the struggles his staff has had of late, Rothschild said there wasn't one specific aspect to point out.

"It's not one thing. It doesn't just happen with one thing; it's different things for different guys," Rothschild said. "But first-pitch strikes and things like that haven't been good. It's just a bunch of different stuff that has been reviewed and talked about and tried to be corrected.

"With each individual, you go with what you've seen and what needs to get corrected. We talk about it, and if it's something mechanical or pitchwise or gripwise or whatever, we do it in the bullpen and try to correct it there."

The day after Tanaka's 12-run outing, he and Rothschild were in the visitors bullpen at Fenway Park, working on his famed splitter. It didn't have the bite in his previous start it had at earlier points this season.

The Yankees also have spent time reviewing their pitchers to see if any are tipping pitches, Boone said earlier this weekend.

"It's a matter of just continuing to dive in with each guy, where we can make small little adjustments, and attacking the game plan in the best way possible," Boone said. "Making sure we're leaving no stone unturned in terms of making the guys make whatever little adjustments or subtle things they need to change -- and also not overreacting to a bad week of baseball."

He might be avoiding the overreaction, but Sabathia admitted that this stretch has been "frustrating."

"We've been the reason why we've been losing games," he said, speaking for the pitchers. "We want to turn that around."

New York gets its chance to do just that Sunday night, when right-hander Domingo German takes the mound. At 12-2 with a 4.03 ERA, he has been arguably the Yankees' best pitcher this season. German's most recent start didn't go well, though, as he gave up eight runs -- all earned -- in an outing at Minnesota on Monday in which he failed to get out of the fourth inning.

German has been sharp for the Yankees when pitching immediately after losses this season, though: He is 5-0 in such appearances. New York is hopeful for that version of the slender righty to show up in the series finale as it seeks to stave off a Red Sox sweep.

"Crazy things happen in this game," Yankees right fielder Aaron Judge said. "You have a couple weeks where every ball is falling, pitching is doing well, and then you have a couple weeks where the offense can't get it going or the pitching can't get it done. That's just part of it. The biggest thing is making sure we can learn from our mistakes, making sure we can improve on this next time we face these guys."