Cubs 3 Up, 3 Down: Jason Heyward Powers Up

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(670 The Score) The Cubs returned from the All-Star break with hopes of a strong second half ahead. They started it right with a three-game sweep of the Pirates at Wrigley Field over the weekend in a series that featured three quality starts and 22 runs from the Cubs.

Here are the latest trends surrounding the Cubs:

THREE UP
1.) Heyward's power up
The Cubs are finally getting the offensive production they envisioned from outfielder Jason Heyward, who's enjoying his best season in years. Heyward hit his 15th homer in an 8-3 win over the Pirates on Sunday, marking his most in a season since hitting 27 in 2012. He has accomplished this in 86 games and 345 plate appearances.

Heyward's power has been no fluke. His isolated power (ISO) is at .199 for 2019, which would be the second-best mark he has ever posted. Heyward's 115 weighted-runs-created-plus is also the best mark he has posted in his four years in Chicago.

2.) KB at his best

Not only has third baseman Kris Bryant come back strong from his injury-plagued 2018 season, but he's back at his best form.

Entering Monday, Bryant owns a .400 weighted on-base percentage -- a career-best mark for him -- and a 148 wRC+ that ties his previous high from his MVP 2016 campaign. Bryant has a slash line of .296/.404/.552 in 2019.    

3.) Backing it up

These days, many teams struggle to find one catcher good enough to call a starter. The Cubs are fortunate to have two of those players with Victor Caratini proving to be an excellent backup for Willson Contreras.

Caratini is second among National League catchers -- with a minimum of 100 plate appearances -- in wOBA (.375) and wRC+ (132), trailing only Contreras. 

THREE DOWN
1.) Left without an answer
It's no surprise the Cubs are searching for a left-handed reliever to bolster their bullpen. They rank 23rd in MLB in opponents' wOBA when a left-handed reliever faces a left-handed hitter, with lefties slashing .286/.334/.426 (.323 wOBA) against Cubs southpaw relievers.

Veteran left-hander Mike Montgomery hasn't proved to be a left-handed specialist, with his struggles the worst on the team. Lefties are slashing .500/.512/.868 against Montgomery.    

2.) Strop's struggles

Pedro Strop has been one of the Cubs' most consistent relief arms since arriving in Chicago by trade in 2013, so his scuffling has been unusual.

Strop surrendered a game-tying three-run homer in the Cubs' 4-3 win over the Pirates on Friday afternoon. It elevated his ERA to 5.06 in his injury-shortened campaign. Strop has been plagued by the home run ball, allowing 1.69 homers per nine innings. That's in contrast to the 0.60 mark from his previous two seasons and that same number over the span of his career.

3.) Second-guessing Russell

Manager Joe Maddon is mixing David Bote, Robel Garcia, Daniel Descalso and Addison Russell in at second base. In a season for Russell to prove his worth, he hasn't done much to emerge for the Cubs.

Russell has a .302 wOBA and 84 wRC+ in 2019, compared to career averages of .304 wOBA and 88 wRC+. In other words, Russell is what he has always been -- an average plate presence who brings strong defense.

Chris Emma covers the Bears, Chicago’s sports scene and more for 670TheScore.com. Follow him on Twitter @CEmma670.