Ryan Zimmerman hits a three-run homer against the Cubs during the fourth inning of Saturday’s 9-4 win. (Nam Y. Huh/Associated Press)

Much of this season, like so much of the past few Washington Nationals seasons, was spent waiting for Ryan Zimmerman. So many injuries sidelined him, so many cold stretches inspired questions about his longevity, that his managers and teammates have practiced answers to questions about his value to their team.

Those answers are almost always the same: When he gets hot, he changes games. When he is playing, he provides a steadying hand. The Nationals are waiting for Zimmerman no more. After weeks of warming, his bat caught fire Saturday, exploding for two homers and six RBI as the Nationals beat up the Chicago Cubs, 9-4. They can win the series with a victory Sunday night, and Max Scherzer will pitch that game.

“We have to try to win every series,” Zimmerman said. “You can’t try to get it all back at one time. You have to go out there and try to win every day.”

Jon Lester started Saturday’s game for the Cubs, and that didn’t seem to bode well for the Nationals, who tend to struggle against left-handed pitching. Then, during batting practice Saturday, they lost one of their key right-handed weapons when they learned that Anthony Rendon did not feel well enough to play.

Rendon got hit by a pitch in his left wrist Friday but played through it to finish the game. Though X-rays on the wrist were negative, the team has yet to offer any clarity on the severity of the issue. He has been one of the Nationals’ more formidable right-handed options, and losing him against left-handed all-star Lester qualified as a significant blow.

Zimmerman, as well as he has hit lately, did not seem the likeliest man to step up in Rendon’s absence. He entered the day 3 for 19 in his career against Lester and 4 for 40 at Wrigley Field since the start of 2015, a stretch of struggles that included the day he left a dozen men on base as the Cubs walked Bryce Harper over and over. His memories here are not positive, particularly in the cleanup spot where Manager Dave Martinez moved him Saturday.

But after Harper blooped a single to right in the first, Zimmerman worked an eight-pitch at-bat that culminated in a two-run homer to deep left-center. Zimmerman is hitting .349 with four homers since returning from the disabled list in late July.

“If we can continue to get him going the way he is now,” Martinez said, “that’s going to be a huge addition.”

Zimmerman isn’t one to volunteer his thoughts but more of a steadying presence, a taken-for-granted example for the rest of the Nationals. He runs out every groundball. He avoids on-field blowups. If his answers to reporters are somewhat boring, they are not causing his team trouble. The 33-year-old has never been much of a cheerleader, or the kind of guy willing to confront his teammates when things go wrong. But he is as consistent as they come, his baseball instincts honed by more than a decade here.

So when Zimmerman pointed to the dugout after Tanner Roark tried to pick off Anthony Rizzo in the first inning, Martinez held up his hand to tell the umpires to wait. Eventually he asked them to review the play. Zimmerman was right, and Rizzo was ruled out on replay. Martinez often jokes that some players are less trustworthy on calls like that than others.

“When he needs to be vocal, he [is], in a very private setting. He doesn’t say much, but when he does say something, the guys take it to heart,” Martinez said. “They respect him a lot. I respect him a lot. He’s a big part of our success.”

When Zimmerman speaks, he means it. And when he hits, he really hits. He is hitting now. Zimmerman nearly hit a second home run when he whacked a line drive to deep center in the third. The ball sunk near the warning track, which meant he settled for a sacrifice fly. By that time, Zimmerman led the Cubs 3-0.

Zimmerman homered again in the fourth, a swing that drove in his fourth, fifth and sixth runs. For much of the first few months of the season, Rendon was the indispensable force in a banged-up lineup that struggled against left-handed pitching. Saturday, in large part because of Zimmerman tying his career high in RBI, that now-healthy lineup scored six runs in the fourth. The team looked just fine without its third base stalwart.

Daniel Murphy is also reemerging, and he hit a two-run homer to left-center in the fourth. Murphy was hitting .188 just more than a month ago. After going 3 for 4 Saturday, he is hitting .308. Matt Wieters reached base five times, going 3 for 3 with two walks.

“We’ve been grinding out at-bats better than we were,” Zimmerman said. “[The lineup is] getting longer and deeper than it’s been all year.”

Roark benefited from the outburst and continued his recent stretch of strong performances with 7⅔ innings in which he allowed two runs. Roark is pitching to a 1.21 ERA in his past four starts and has not pitched fewer than seven innings in any of them.

His continued success will be necessary if this team is to make a run at the National League East. Zimmerman’s success will be a long-awaited bonus, something the Nationals had learned to live without, knowing full well he can change their lineup dramatically.