DENVER -- Madison Bumgarner has been around a while. He’s left his mark on the game of baseball, particularly with his legendary 2014 postseason for the Giants and by helping San Francisco win three World Series titles. But the glory days seem like eons ago now, as the big left-hander struggles to rediscover his old form with the D-backs.

“I’ve been the weak link,” said the 2014 National League Championship Series and World Series MVP, who repeated himself for emphasis. “I’ve been the weak link.”

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As he got ready to head to the team bus following the D-backs’ 7-4 victory over the Rockies in their series finale at Coors Field on Sunday afternoon, Bumgarner discussed what he sees in an Arizona starting rotation that has posted a 3.29 ERA since July 22. The first name Bumgarner mentioned was Tommy Henry.

The rookie left-hander held the Rockies to two hits through five scoreless innings Sunday before getting into some sixth-inning trouble.

It was the 25-year-old’s third career start, and he was charged with three runs on five hits, as he walked three and struck out three over 5 1/3 innings. Over his last two starts, Henry has a 2.92 ERA. (He gave up only one run over seven innings against the Pirates on Tuesday.)

“I’m still getting to know Tommy,” Bumgarner said. “But from just the little bit I’ve seen him, I like what I’m seeing.”

What Bumgarner and the D-backs saw from Henry, ranked by MLB Pipeline as the organization’s No. 12 prospect, was poise from a mound that has eaten up countless pitchers before him. In the most hitter-friendly environment in the Majors, Henry silenced the Rockies’ bats for five innings -- on the heels of Arizona’s shutout win on Saturday night.

For a time, it looked as though the D-backs might challenge the all-time record for most consecutive scoreless innings pitched at Coors, which is 17. Arizona pitchers tossed 15 scoreless frames from the eighth inning of Friday’s series opener through the fifth inning of Sunday’s contest.

“I felt like today was another step,” Henry said. “I felt like I was in a decent groove most of the day. … I threw a lot of curveballs today. It was one of those things where if it feels good and plays well, just kind of run with it.”

It’s been feeling good and playing well for the D-backs, who have won eight of their last 12. On Sunday, Henry got plenty of run support, led by Christian Walker’s 4-for-5 performance -- the slugging first baseman drove in four runs and finished a triple shy of hitting for the cycle.

But Arizona’s recent success is in large measure thanks to the rotation’s overall excellence. Zac Gallen threw seven scoreless innings and gave up just two hits Saturday, lowering his second-half ERA to 1.14 over five starts. Merrill Kelly, who is enjoying a breakout season at age 33, owns a 1.86 ERA over his last eight starts. And Zach Davies, despite missing some time with right shoulder inflammation, has a 3.30 ERA over his last eight starts as the soft-tossing righty continues to induce weak contact.

It’s gotten to a point where there is a legitimate question as to whether the D-backs have the makings of one of the NL’s better rotations.

“Merrill has been really good,” Bumgarner said. “He kind of reminds me of Ryan Vogelsong, [another journeyman who found late-career success with the Giants]. I think he’s starting to realize how good he is now. I’d trade my stuff for his in a minute. And Zac, nobody’s seen his ceiling yet. And Davies is doing his Greg Maddux thing.”

The D-backs continue their quest to return to contention for the first time since a Wild Card postseason berth in 2017, and if they’re going to get there, they’ll need their starters to continue trending in the right direction.

Bumgarner, whose ERA since signing with the D-backs prior to the 2020 campaign is 4.70, knows he’s got some work to do to join the rest of the pack, which has jumped ahead of him.

“I’m working on something right now,” Bumgarner said. “Something mechanical. I don’t want to say anything about it yet. If we’re right, then it’ll be really good.

“If it’s not, then you’ll never know about it.”