If this is a preview of an entire season, the playoffs will be returning to Houston for the second time in three seasons.
Both Keuchel and McCullers were injured down the stretch last season. Had they pitched the way they're pitching now, the Astros would have gone back to the playoffs.
"We feed off their success," reliever Chris Devenski said. "Look at what Lance did today."
McCullers pitched 6 2/3 shutout innings and struck out eight in a 2-1 victory over the Angels on Thursday afternoon. On Wednesday night, Keuchel tossed his fourth straight gem, allowing one earned run in seven innings of a 5-1 victory. Houston has won seven of the duo's past eight starts. Combined, the Astros are sporting a 2.08 ERA.
Here's some Statcast™ data to understand how good Keuchel and McCullers have been this season. During Keuchel's 2015 AL Cy Young Award-winning season, balls were not hit hard -- an average exit velocity of 88.3 mph, among the best in baseball.
That number soared to 91.4 mph last season. This year, he's inducing even more soft contact than he did in 2015 -- 85 mph.
As for McCullers, his knuckle curve is one of baseball's best breaking pitches -- an average spin rate of 2,839 rpm. Only Dellin Betances (2,915 rpm), Trevor Cahill (2,892 rpm) and Mark Melancon (2,843 rpm) are better.
"They're two of the best pitchers in the league," second baseman Jose Altuve said. "It's a privilege to play defense behind them. As a team, I feel like we're starting to get going. We just have to keep playing hard."
There are plenty of other reasons to like these Astros. They have one of the five best players in baseball in Altuve. They have one of the most dynamic in outfielder George Springer.
In shortstop Carlos Correa and third baseman Alex Bregman, they have two young players who could both be cornerstone-type players. In the bullpen, Devenski has emerged as one of the best in the game.
Even with right-hander Collin McHugh on the disabled list with a cranky shoulder, Houston has confidence in the rest of its rotation: Charlie Morton, Mike Fiers and Joe Musgrove. But it's Keuchel and McCullers who are capable of taking the franchise to another level.
"We've found different ways to win games," manager A.J. Hinch said. "I don't think we've played our best yet, and I think that's an exciting part for us to really put it all together. There are areas for us to get better."
At 11-5, the Astros have the best record in the Majors. Sure, it's too early to dwell on 11-5. On the other hand, they were 5-11 at this point last season on their way to a 7-17 start. Houston missed a playoff berth by five games.
"We were playing uphill," Hinch said. "We needed three or four months of exceptional baseball before feeling like we were back."
But the Astros were never close to being this good. Until Bregman and first baseman Yulieski Gurriel arrived after the All-Star break, their offense was hit and miss. Once Keuchel (shoulder) and McCullers (arm) went down with a month remaining, Houston's rotation couldn't make up the difference.
The Astros' offseason story line was general manager Jeff Luhnow adding experience and production in Carlos Beltran, Brian McCann, Norichika Aoki, Josh Reddick and Morton.
As much as those veterans have given the Astros a different look and a much deeper lineup, they were still crossing their fingers that Keuchel and McCullers would bounce all the way back.
And that's the good news: both have. Keuchel's ERA is a microscopic 0.96 after four starts in which he has looked at least as good as he did during his 2015 AL Cy Young Award season.
And there was McCullers on Thursday afternoon throwing 100 pitches, 50 of them hard curves that makes his 93-mph fastball even better.
McCullers got six of his eight strikeouts on curveballs and nine of his 14 swings and misses. He didn't allow a runner to reach scoring position until the seventh inning.
"It makes it very dangerous based on the styles we all possess," Keuchel said. "On back-to-back nights, you're not going to get the same look. Me and Lance probably vary the most, which is good for both of us. I think our staff doesn't get enough credit, but a lot of the guys don't have the track record yet or the longevity."
So on a day like Thursday when the Astros got just three hits and scored both runs on solo home runs by Beltran and Jake Marisnick, they still had enough for an 11th victory.
"This is by far the most talented and fun team I've been on," Keuchel said, "and that's including college, high school. Some pretty fun teams, but not to the level like this.
"We're still trying to hit on all three cylinders. We've hit on one or two here and there. We're still looking for all phases of the game, and that's not a bad thing in April. We want to be hitting in August. If we can get five games over (.500) every month, we'll be sitting pretty."
Richard Justice is a columnist for MLB.com. You can follow him on Twitter @richardjustice.
This story was not subject to the approval of Major League Baseball or its clubs.