CHICAGO -- When Ian Happ blasted a fifth-inning home run off Marlins starter Jose Urena on Wednesday night, Justin Grimm, Pedro Strop and their fellow Cubs relievers did a little dance for the benefit of the bullpen cameras. They were back in action a couple innings later, when Kyle Schwarber reached the seats with an opposite-field homer off David Phelps.
But it's not the move to new quarters under the left-field bleachers that has energized the Cubs' relief pitchers. They were an animated bunch as far back as 2015, when Strop used to empty out a bubble-gum bucket and play it like a drum to Starlin Castro's walk-up music. These guys know how to have a good time.
The difference for the Cubs this season is how well their bullpen is pitching.
While Theo Epstein is always on the lookout for ways to make a good thing better, he shouldn't have to do a midseason rebuild of the Cubs' bullpen this time around, as he's done the past couple of years. That's a credit to the job being done by Wade Davis and a handful of other relievers who weren't with the Cubs this time last season -- the homegrown C.J. Edwards and imports Mike Montgomery, Koji Uehara and Brian Duensing.

They've turned what previously was a weakness into the strength of a stuck-in-second gear Cubs team.
Manager Joe Maddon said so the other day.
"The pitching has not been that awful," Maddon said. "For me it hasn't been, by any means. We have a lot of good [starters] and they're gotten progressively better. The bullpen has been really good. Not just pedestrian, but really good."
Epstein has never been a big believer in doing top-end contracts with relievers. That's why he didn't compete to keep Albertin Chapman after sending Gleyber Torres to the Yankees to get him last July. But it will be interesting to see if Epstein digs deep to keep the 31-year-old Davis from hitting the free-agent market this offseason.
Nothing against Kenley Jansen, Zach Britton, Andrew Miller, Mark Melancon or Chapman, but Davis has quietly been the best reliever in the Major Leagues since 2014, when Ned Yost and the Royals assigned him permanently to the bullpen.
Davis' numbers over almost three and a half seasons aren't just great, they're obscene. He's worked 203 innings over 206 appearances as a setup man or closer, compiling a 1.15 ERA and ratios of 5.0 hits, 0.2 home runs and 11.6 strikeouts per nine innings. Davis' 360 ERA+ in this extended period is better than Mariano Rivera's from 2008 (316), which is considered his best season.
Since taking over for Greg Holland as Kansas City's closer, Davis has gone 56 for 60 in save situations. That includes a 12-for-12 performance this season, with an 0.79 WHIP and 0.89 ERA over 20 1/3 innings.
But while Davis is the headliner, his supporting cast has been almost as impressive. Getting leads to the closer (Hector Rondon in 2015, Chapman last year) has been an issue for the Cubs under Maddon, with the bullpen as a whole ranking second in the National League with a 3.06 ERA.

To use Maddon's barometer, the bullpen wasn't "awful" the previous two seasons, but it was a hands-on-the-wheel experience for Epstein's front office. Travis Wood, Strop and Rondon accumulated 387 appearances in 2015-16, getting the job done far more often than not. But the heavy use of Chapman last October indicated how fragile confidence in relievers can be.
Edwards, the skinny right-hander with the wicked four-seam fastball, was promoted from Triple-A Iowa in late June last season. He and Montgomery, who was acquired from the Mariners for Dan Vogelbach and Paul Blackburn on July 20, were the two setup men Maddon trusted the most last fall, and they've been consistently excellent this season.
Both are worthy of All-Star consideration, although Edwards is the one with numbers that could be impossible to ignore. He's allowed only six hits over 22 2/3 innings (with 11 walks and 31 strikeouts) in 25 appearances.
Uehara, the 42-year-old former Red Sox closer, and Duensing were signed as free agents last offseason. They're holding up well alongside Strop and Rondon, giving Maddon the luxury of a seven-deep cast. Grimm has been up and down between Wrigley and Triple-A, and the Cubs love the job lefty Zachary Rosscup is doing at Iowa.
None of this means Epstein won't add an arm in July; that's what he does. But he's not going to need to trade a top prospect like Torres to get his bullpen ready for October.
Maddon's got the pieces he needs to win a second straight NL Central and head into October looking to win it all again.