Kevin Kiermaier is set to return, and should make the Rays way better

On May 21st the Rays were looking to finish the first quarter of the season above .500 in their 40th game of the season, but in the fifth inning Kevin Kiermaier went for a diving attempt on a line drive to center field and the season changed. Kiermaier immediately ran to the dugout and everybody knew something was very wrong and unsurprisingly it was announced he broke his hand. Two days later things got worse as the Rays announced Kiermaier would require surgery to repair his broken hand and would be out six to eight weeks.

In the 48 games since the Rays have gone 14-34. In about 2 months the Rays went from a team sitting at 20-20 that was waiting for the return of Logan Forsythe to one of the worst records in all of baseball. The Kiermaier injury isn’t all to blame, but it certainly didn’t help the situation.

What have the Rays missed while Kiermaier has been on the DL?

The first thing you think about when you hear the name Kevin Kiermaier is his otherworldly defense in center field. He can make plays that not many on this planet have ever been able to accomplish using his speed, ability to make difficult catches, and his arm. Most defensive players are able to make plays because of one special attribute, but Kiermaier has strengths that place him among the best in the league in make plays in ever manner imaginable.

Yesterday at ESPN (behind paywall), Joe Peta discussed what has gone wrong in the first half for the Rays and he brings up this nugget.

The Rays were saddled with a below-average defense over the first half of the season, which is a very unusual thing to weigh down this franchise. And in fact, after 40 games, all seemed normal as the Rays were the second-ranked team in adjusted defensive efficiency and playing .500 ball. Yet, they finished the first half ranked 20th, which means they were among the worst fielding teams in baseball in the season's second quarter -- when they went 13-28.

Park Adjusted Defensive Efficiency (PADE) is used at Baseball Prospectus and their figures can be found here. Simplistically PADE is calculated by subtracting BABIP and reached on error percentage from 1 to get what percentage of plays are made by the defense. The full formula is as follows:

1 - ((H + ROE - HR) / (PA - BB - SO - HBP - HR)

Kiermaier is only one man and for how great he is he can’t cause the fall of the whole defense. Desmond Jennings (229 innings), Brandon Guyer (129 innings), Mikie Mahtook (78 innings), Steven Souza Jr. (15 innings) and Jaff Decker (8 innings) attempted to fill the void in center.

PLEASE NOTE: Defensive metrics contain a very high variance especially in samples this small. With that said: The results weren’t good any way you slice it and there was definitely a massive drop off from the reigning Platinum Glove winner.

The five replacements combined for -6 DRS and -6.5 UZR over a quarter of the season. At Kiermaier’s rate you conservatively pencil in +4-5 runs saved and I don’t think there would be much argument to be had. If you wanted to feel frisky last year Kiermaier put up 42 DRS and 40.0 UZR/150, so you could aim as high as 10 runs.

11 runs on defense is approximately 1.25 dWAR that Kiermaier reasonably could have saved and as much as 1.75 dWAR if you wanted to not regress last season’s totals.

Kiermaier isn’t just a one trick pony.

Even though the first thing you think about when you hear Kiermaier’s name is his highlight real defense his offense isn’t bad as he’s been a plus there as he has a career 105 wRC+ over 1,036 plate appearances in his career and a 103 wRC+ through 137 plate appearances this season. That is a solid league average bat and shouldn’t be overlooked.

Desmond Jennings did a pretty good job trying to hold down the fort during Kiermaier’s absence while only giving up a little on offense and a drop off defense mostly because of his weak arm that generated -3.3 of the -4.6 UZR. A drop off was expected, but this was probably the best case scenario where you lose around 10 runs due to the Kiermaier injury. However, Jennings hit the disabled list and was unable to see it through.

Brandon Guyer when forced into an everyday role isn’t a great offensive option and that has shown through. He wasn’t a black hole, and his defense was the best outside of Decker who only had a handful of innings to show off his skills. His -1.0 runs below average prorated to the 212 plate appearances would have roughly been worth -3.5 runs. His defense prorated would come out to around -1.5 runs, so he would have been about the same as Jennings at about 10 runs worse than Kiermaier. However a trip to the disabled list couldn’t be avoided just as an inside fastball fails to avoid Guyer. Somehow Guyer’s injury wasn’t related to a hit by pitch.

That batting line by Mikie Mahtook is something else. He was able to manage -5.5 runs in 36 plate appearances. He likely wouldn’t play at that kind of pace, but he did manage to cost the Rays 6.1 runs above average in only 78 innings or just over eight games.

Steven Souza Jr. ran good at the plate, but it was only eight place appearances where he went 3 for 8 with a 2B and 3B. He also got benched for lack of hustle during that stretch. His defense wasn’t good as he had at least one memorable blunder where he dropped a flyball as he approached the wall at Fenway Park.

Jaff Decker is what he is, but it was only eight innings that cost the Rays 0.2 runs.

In total offensively the replacements put up -6.3 runs above average. Kiermaier for his career has put up +12.2 runs in 1,036 plate appearances for his career. If you wanted to be aggressive you could say he would put up around +2 runs in those 212 missed plate appearances. So Kiermaier offensively would have given the Rays somewhere between five and seven additional runs.

Kiermaier is back and that’s a great thing.

Combining the 11 to 16 runs of defense, based on your level of optimism, with the 6 to 9 runs of offense Kiermaier would likely have produced 17 to 25 runs or 1.9 to 2.8 fWAR (assuming a 9.0 run environment) over the replacements. That is pretty massive. That doesn’t make the difference of a team going 20 games under .500 without him, but it starts to paint the picture when you have four of your outfielders on the DL at the same time.

In all but the most improbable scenarios Kiermaier’s return is too late to make any real run as the Rays weren’t able to keep pace with the rest of the league. This is still a good day worth celebrating as having Kiermaier patrolling center field is a pretty great thing and makes watching Rays games much more enjoyable.