What's wrong with Justin Verlander?

Justin Verlander struggled mightily again on Tuesday. By allowing seven earned runs in five innings, the Tigers' presumptive ace raised his season-long ERA to 6.49. The general hope has been that Verlander is merely experiencing a bump in the road, and a 22.2 percent strikeout rate lends credence to the idea that sooner or later he's going to figure it out.

However, there are troubling signs for Verlander going forward. Given the standard caveat that after 30 innings we don't want to proclaim that all trends are final, there are some trends that he needs to reverse.

The most obvious: home runs

I don't expect that Verlander will continue to give up home runs on 14.0 percent of fly balls he allows, but the homers he has allowed so far have not exactly been cheap, especially the shot by Oakland's Khris Davis last week.

Considering the fact that Verlander has trended more and more towards being an extreme fly ball pitcher over the years -- his ground ball rate sat easily at a career-low last year at 34.6 percent, and he's dropped further to 34.3 percent this year -- homers are going to be a problem unless he can corral his fastball, as he's already allowed six (!) dingers on that pitch.

Sitting, waiting, wishing

Part of Verlander's problem is that hitters have found an adjustment to him: waiting. Batters are only swinging at 44.4 percent of his offerings this year, also a career low. However, this has not coincided with a drop-off in swings at pitches in the zone: at 67.5 percent, hitters are about as aggressive as they have been throughout Verlander's career. The problem is that he is not fooling them with pitches outside the zone: his 23.6 percent O-swing rate is the lowest that Verlander has posted since 2007. Not surprisingly, his two highest rates were during the two best seasons of his career, 2011 and 2012.

What does this mean for Verlander? For one, batters are extending plate appearances against him and shortening up his outings. Verlander has the eighth-highest rate of pitches per plate appearance in the MLB (4.24), which is forcing him to average 18.2 pitches an inning so far (9th-highest in the MLB). The Tigers are better-prepared to handle shorter outings from starters than in the past, but it doesn't help when Verlander has only made it through the seventh once in six starts.

Furthermore, Verlander may be more prone to making mistakes when he's in the middle of lengthy battles. Davis homered on the seventh pitch of the at-bat last week. Carlos Santana hit a solo shot on the sixth pitch of an at-bat on April 22, and batters have a .440 weighted on-base average (wOBA) in at-bats that go to full counts against him.

Perhaps the single weirdest thing about Verlander's profile through his first six starts are his platoon splits. Lefties are batting .246/.297/.441 against him, while righties are scorching him to the tune of a .299/.378/.600 mark. That's incredibly odd, although he has posted consistently negative platoon splits since the beginning of 2013. The reason for this may be a loss of his effectiveness with the his breaking pitches, which is forcing Verlander to turn to the fastball inn predictable hitters counts. Verlander's fastball has been a league average pitch since 2013, a steep drop-off from his heyday from 2009 to 2012.

What does this mean?

In short, Verlander has some adjusting to do. His fastball is showing signs that it's too hittable to compensate for the loss of feel in his breaking pitches, and it may be the reason that righties are teeing off on him. While he has been able to strike nearly a batter per inning so far, he isn't fooling hitters with pitches out of the zone, outside of the occasional high fastball. However, Verlander needs to sharpen his offspeed pitches in order to keep hitters off that fastball, which in turn will alleviate the other problems plaguing him in 2016.