After coming to the Mets in a trade before last season that he was the headliner of (even though Robinson Cano was the "bigger" name), Edwin Diaz had a brutal first season in New York.
Diaz had a 5.59 ERA and 1.38 WHIP in 58 innings, allowed an eye-popping 15 homers (2.33 per 9) and lost his closer job while being relegated to mop-up duty at times.
It was a hard fall for a 25-year-old who was arguably the best closer in baseball in 2018.
But while Diaz's 2019 was a disaster, there are a bunch of reasons to believe it will be a blip. Here's why...
His fastball was still elite in 2019
While Diaz was struggling mightily, he was still striking out 15.36 batters per 9 -- a slight increase from his rate in 2018 and the best rate of his career.
A deeper dive shows that Diaz's fastball velocity and whiff rate were among the best in baseball last season, and that the spin rate on his fastball was still well above average.
The problem was that when hitters made contact, it was often loud contact, with the hard hit rate allowed by Diaz among the worst in baseball.
Harnessing his slider in 2020 and locating his fastball better are keys to fixing the above.
He was unlucky in 2019, and the advanced numbers show it
While Diaz's ERA was an unsightly 5.59, his FIP (4.51) and xFIP (3.07) are better indicators of how Diaz's results should've looked in 2019 and a good predictor of what should be expected in 2020.
FanGraphs' projection for this season has Diaz posting a 2.88 ERA, cutting his home run rate by more than half, and his BABIP allowed dropping 69 points.
Again, a lot of the issues for Diaz in 2019 revolved around him struggling with his slider and his location in general. But there was also bad luck involved. And a regression to the mean should be expected.
The ball should be different in 2020
As fly balls that used to be outs or doubles started sailing out of ballparks at record rates in 2019, there was plenty of discussion about a "juiced" ball. And while the ball might not be much different in 2020 due to the length of manufacturing times, one issue that bothered pitchers in 2019 could be fixed.
The slickness of the 2019 ball, which impacted the ability of pitchers to grip certain pitches, should be less of a concern this season. And part of that has to do with how MLB plans to enforce rules regarding substances on the baseball in 2020.
"Choosing to look into that at all and enforce it suggests to me that the balls won't be as slick," Dr. Meredith Wills -- an astrophysicist and contributor to The Athletic -- told SNY this offseason. "Because otherwise, you're going to have a lot of trouble justifying (the rule)."
If the ball is indeed easier to grip, that should only help Diaz.