The 10 worst MLB players in June

A lot can happen over the course of an MLB regular season. That’s why we try to resist prematurely jumping to conclusions with regard to player and team performance. But now that we’re more than halfway though the regular season, we can start putting more weight behind the numbers we have at our disposal.

After spotlighting the best hitters and starting pitchers from June, we’re doing the same for those guys on the opposite end of the spectrum. Once again, we’re going to rank hitter performances by wRC+, while Skill-Interactive ERA (SIERA) will be used for the starting pitchers.

It’s safe to say that these 10 players are happy the calendar has flipped to July.

June’s Five Worst Starting Pitchers

It seems like pitchers are always evaluated by the same traditional metrics, such as win-loss record, ERA, WHIP, strikeouts per nine innings and walks allowed per nine innings. This is exactly why we’re going against the grain and evaluating pitcher performance by SIERA.

SIERA attempts to measure the underlying skill of a hurler, but unlike FIP and xFIP, it doesn’t ignore balls put in play, and also attempts to give a more accurate picture as to why certain pitchers are better than others. A good SIERA is just like a good ERA — the lower the better.

Here are the five hurlers who struggled the most in June.

Lucas Giolito is one of two Chicago White Sox pitchers on this list. If we had bumped it out a little more, Dylan Covey would’ve made it three. Giolito did post a 2.38 ERA in 45.1 innings last season, but a 4.49 SIERA told a bit of a different story. Regression has hit hard so far in 2018, as his strikeout rate matches his walk rate (13.2%) and his 5.99 SIERA is much more in line with his current 6.59 ERA.

Although Bartolo Colon is finding a way to climb up the all-time wins list, his overall performance hasn’t been overly stellar. His 3.9% walk rate is indicative of what he’s done throughout his career, but the batted-ball profile doesn’t look great. The 45-year-old’s 22.3% line-drive rate, 48.1% pull rate, and 44.3% hard-hit rate all in danger of becoming career-worst marks, while his 13.7% soft-hit rate would be his worst since 2014 with the New York Mets (12.9%).

Jason Hammel hasn’t enjoyed his time with the Kansas City Royals. Well, on the field, at least. After a rough 2017 campaign, more of the same is happening as certain statistics continue a downward trend. The veteran right-hander posted a career-high 24.2% strikeout rate for the Chicago Cubs in 2015, and his current 14.5% mark puts him on track for that number to decrease for the third consecutive year. Allowing hard contact at a 45.8% rate doesn’t help, either.

Reynaldo Lopez had the opposite experience with Chicago over the past two seasons. He didn’t drastically outperform his peripherals in 2017, but has managed to do so over the past three months. One pitch he’ll likely hope to get on track is his changeup. After limiting opposing hitters to a 103 wRC+ and .304 wOBA last year, those numbers have increased to 160 and .386, respectively, in 2018.

Frankie Montas is racking up the wins for a suddenly-hot Oakland Athletics club, but he’s dodged plenty of bullets along the way. His start on June 26th is a great example — he allowed 6 runs on 8 hits, 3 walks, and 1 strikeout in 3 innings against the Detroit Tigers, but received a no-decision because Oakland ended up winning the game. Montas’ 15.2% strikeout rate and 7.7% swinging-strike rate are both terrible compared to past exposure in the majors.