SAN FRANCISCO — Don’t look now, but the Cubs’ starting rotation finally might be starting to fulfill the promise manager Joe Maddon suggested in spring training when he called it the best rotation on paper he has had in four seasons in Chicago.
That’s high praise, considering the last three produced the top rotation ERA in the National League during that span.
But after Kyle Hendricks’ best start of the season Monday and Jose Quintana’s six scoreless innings in a 2-0 victory Tuesday against the Giants, a rotation that has been the weak link on a strong team suddenly has a streak of 15 2/3 innings without allowing an earned run.
“Obviously, those two guys have got to feel pretty good about themselves right now,” Maddon said.
‘‘This game is contagious, and hopefully that becomes a contagious thing and we all get on that run,’’ said ace Jon Lester, who has been the lone reliable constant in the rotation all season.
Yu Darvish still is sidelined for who knows how long, and Tyler Chatwood still leads the planet in walks. But if the performances of Hendricks and Quintana the last two nights are the start of something, the rotation Maddon and the rest of the Cubs have been waiting to see might be arriving just in time for another big second half.
‘‘I hope so,’’ Hendricks said. ‘‘Jon’s been there all year for us, so we’ve all been trying to feed off of him. And luckily I was able to have a good one, and hopefully I can build on it. Q has been throwing the ball really well, so hopefully he can go out and build on what he’s been doing.’’
Quintana allowed three hits and retired nine of the first 10 batters he faced and seven of the last nine, with two double plays among the seven.
‘‘That’s really important for us,’’ Maddon said of getting the kind of rotation production behind Lester that Hendricks and Quintana showed — and that has been missing on a consistent basis all season.
“We saw that a lot out of Q last year,” Maddon said. “The difference [Tuesday] was the curveball strike. The curveball command. The curveball chase. That was part of his repertoire [Tuesday] whereas that has not been part of it [earlier this season]. It has just been fastball, fastball, fastball.
“The curveball has not been as effective and the changeup hasn’t. Today he had two of the three working well. And when he’s really good he’s got all three working so it was a nice first step.”
While many of the starters have struggled with mechanics or injuries, the bullpen and fielding have excelled, and the hitting has heated up in recent weeks.
‘‘We need the starters to lock in kind of like Kyle did [Monday],’’ Maddon said.
And Quintana, who has given up a combined two runs in 12 innings in his last two starts, both victories.
“I said to Kyle, `I’ll try to follow you,’ ” Quintana (8-6) said. “When I say ‘I want to follow you,’ I try to throw like him, and try to throw like when Jonny pitches really good. It’s really good competition for us, and that’s the best thing for the team.”
Tuesday marked the start of the final full turn for the rotation before the All-Star break. It might be a huge week for the starting pitchers in pitcher-friendly ballparks on the West Coast.
‘‘I think every week is big for us,’’ Lester said. ‘‘But the parks [this week] do benefit us a little bit more so than the hitters, which is nice. Getting out of the Cincinnatis and the Wrigleys when the wind’s blowing out and coming to a place like this for a change.
‘‘But regardless of what park we’re in, we still have to execute our game plan. It’s definitely not a group I’m worried about, that’s for sure. I’ve seen all these guys put runs together. It’s just a matter of maybe just that one last little tweak and get guys getting on that roll.’’
It might go a long way toward boosting a rotation that had sagged to sixth in the NL in ERA (3.87) entering play Tuesday.
And it might go a long way toward reversing a trend that had seen the Cubs trail in 17 of 18 games through Monday.
And what might it mean if others can follow Hendricks’ and Quintana’s leads, even just heading into the break?
‘‘For the sake of the pitchers’ confidence, to finish strongly in the first half, you take that break and you feel better about yourself coming back,’’ Maddon said. ‘‘You feel like you’ve locked into something.’’