All is not lovely in the City of Brotherly Love.

The Philadelphia Phillies enter the second half of the MLB season at 47-43, in third place in the National League East behind the first-place Atlanta Braves and surging Washington Nationals.

It's easy to blame outfielder Bryce Harper, the Phils' gaudy offseason acquisition. But another expensive culprit is an even bigger issue.

Sure, Harper inked a record-breaking 13-year, $330 pact over the offseason and is hitting a mediocre .253 with 105 strikeouts in 90 games for the Phillies. The 26-year-old failed to make the National League All-Star team in his first campaign in Philadelphia. That's a bad look, to put it mildly.

However, at least Harper has clubbed 16 home runs, has a .370 on-base percentage and 2.0 WAR by FanGraphs' measure.

Instead, Citizens Bank Park's infamous boo birds should aim their ire at a different target: Jake Arrieta.

The right-hander signed a three-year, $75 million contract with the Phillies in March 2018. That season, he posted a 3.96 ERA in 172.2 innings. Not disastrous, but far from excellent.

So far in 2019, Arrieta owns a 4.67 ERA and even worse 5.07 FIP with 0.6 WAR. And that's merely the tip of the troubling iceberg.

After posting an average fastball velocity of 94.9 mph in his Cy Young Award-winning season with the Chicago Cubs in 2015—the apex of his career—Arrieta is throwing his average heater at 92.8 mph this season.

Here's how his hard-contact rate has changed in the same span: 22.1 percent (2015), 25.2 percent (2016), 29.4 percent (2017), 27.7 percent (2018), 36.7 percent (2019).