Emma: Cubs' Jake Arrieta Desperately Struggling To Look Like Himself

By Chris Emma--

(CBS) Two summers ago, the buzz in Wrigley Field built well before first pitch when Cubs right-hander Jake Arrieta took the mound.

Then a renewed pitcher chasing history, Arrieta would walk from the Cubs' third-base dugout toward left field with a towel around his neck, and the ballpark would rise to its feet. He'd settle in near the warning track and begin his stretches. The bleacher bums stood and cheered.

Chicago knew it was witnessing something special during his run in 2015, when Arrieta went on a historic pitching pace. He finished the season 22-6 with a 1.77 ERA, which included a 16-1 mark with an 0.86 ERA in his final 20 starts. Arrieta earned the National League Cy Young and became a hero in Cubdom. Every time he started felt like a holiday, met with another exceptional outing.

Tweaks to his mechanics allowed Arrieta to become a dominant force on the mound.

"It never surprised me," Arrieta said of his rise in 2015. "Really, I've expected this my entire career. Even when I struggled in Baltimore, I knew this moment was close. I knew it was close."

Two years later, Arrieta isn't close to that 2015 form. He was pulled in the fifth inning of his team's 7-5 win over the Rockies on Sunday, his most recent disappointing outing in a season that's had too many of them and seen Arrieta's trusted mechanics break down.

Set to hit the market in free agency after this season, Arrieta is now 6-4 with a 4.68 ERA and 1.33 WHIP. A year ago, he was 18-8 with a 3.10 ERA, a step back from 2015 but still a good mark. While his FIP of 4.00 this season would suggest he's not been as bad as his ERA shows, there's a lot to review in this struggle.

Arrieta's fastball velocity is down from its 95-mph range of 2015 to just about 92 mph now. Arrieta has referenced more often to pitching to contact this season out of necessity, but his ground ball rate is down to just 43 percent -- it was 56.2 percent in 2015 -- and his HR/FB rate is at 15.2 percent. Getting strikeouts is a bit more difficult, and pitching to contact has been more of a hazard than anything else.

Cubs manager Joe Maddon pulled Arrieta after 4 1/3 innings and 82 pitches Sunday, with the Cubs leading 4-2 but the Rockies further threatening with the bases loaded. His fifth inning included a double, a walk, a hit by pitch, a four-pitch walk with the bases loaded, a two-run single and a quick hook. Arrieta walked slowly off the mound and toward the dugout looking dejected.

Arrieta has gone past the six-inning mark just once this season, and only three times has he reached the 100-pitch mark. Once the ace of this staff, Arrieta hasn't warranted the faith of Maddon. The Cubs can't trust him to go deep into games anymore.

At his peak, Arrieta could mix his fastball at 95 and work that breaking ball from different angles. It could present with a steep drop or break like a slider. The cutter was also a force on hitters. When in doubt, he could pitch with downward action and get ground balls at a top-five rate. He now battles with every bit of that repertoire. Now, there's no last resort for effectiveness.

Arrieta has referred to his mechanics as the reason for these struggles. His torso often overcompensates its turn forward, and his movement toward the plate is out of alignment. That front foot now finishes a foot to the right of the rubber, which could also explain the command issues.

Those mechanics on which Arrieta relied during his run of dominance two summers ago have disappointed him. He now spends those off days focusing on getting his alignment back in place. There's a lot of work that goes into Arrieta's preparation -- not just the Pilates and treatment but also detailed studying and tweaks to his motion in side sessions.

Ever the savvy perfectionist, Arrieta is working hard to get back on track. He still feels he can be an ace, but it's worth wondering if this is now Arrieta -- at his best, six innings and the chance to win; at worst, a pitcher struggling with his stuff.

It was just two summers ago that tweaks to his mechanics led to a historic run of success. Now, Arrieta is desperately struggling to regain that old form, searching far and wide for a solution.

Chris Emma covers the Bears, Chicago's sports scene and more for CBSChicago.com. Follow him on Twitter @CEmma670 and like his Facebook page.