Hey, the wounds are still fresh, so it seems like a fine time to do some evaluating. This is the Exit Music (For A Player) series. Check out other Exit Music (For A Player) posts here.
Acquired: Via Rule 5 draft from Boston, 2012
Age: 30. He'll be 31 next August
Contract Status: Arbitration-eligible for the first time; Fields won't be a free agent until the 2019 season.
Fields has always been a fairly highly-touted player throughout his career, but just hasn't quite lived up to the billing. Fields was drafted by the Braves in the 2nd Round of the 2007 draft, but he declined to sign and returned to the University of Georgia for his senior season, where he was the SEC Pitcher of the Year in 2008 and helped the Bulldogs to the finals of the College World Series. It worked out for him, because he was taken with the 20th overall pick by Seattle the following year and the Mariners thought he could be in their bullpen by September of that year. Fields wanted $2m to sign, the Mariners offered him $1.5m, which led to a standoff between the Mariners and Scott Boras that wasn't finalized until February 2009.
All throughout his time in the Mariners' organization (2009-2011), Fields struggled with finding the strike zone. In 101IP, Fields struck out 103 batters, but walked 72. So at the trade deadline, Fields was dealt to Boston in the three-team trade that sent Erik Bedard to Seattle.
It was in 2012 that Fields began to show flashes of the 1st Round talent. In 58.1IP Fields struck out 78 batters and walked just 18 between Double-A Portland and Triple-A Pawtucket, but he was left unprotected on the crowded Red Sox 40-Man roster, and the Astros selected him in the Rule 5 draft.
In 38IP for Houston in 2013 he allowed 31H/21ER, 40K:18BB, but also 8HR for a 4.97 ERA on a 1.29 WHIP. The Astros could stomach this in 2013 because they were terrible and Fields had the potential to be a solid reliever, given his cutter...if he could just learn to throw it in the general vicinity of the plate.
Fields took a step forward in 2014, limiting what had haunted him before - walks. Fields did get sent down - having survived the Rule 5 rule of staying on the 25-man roster for the entire 2013 season, but settled down once he returned. He cut his walk rate from 4.3 BB/9 in 2013 to 2.8 BB/9 in 2014, and allowed just two home runs in 54.2IP - much improved from the eight he gave up in 38IP in 2013. Still, his ERA was 4.45 despite a 1.23 WHIP, thanks mainly to a two-week stretch in late April-early May when he allowed 14H/14ER, 4K:3BB in 3IP. That'll kill anyone's ERA. He had some struggles in mid-August, allowing 5ER in 2IP, but that became Fields' M.O: stretches of dominance and strikeouts marked by brief periods of inability to get anyone out.
Thanks to a Spring Training hamstring issue, Fields didn't make his 2015 debut until the end of April. In his second appearance of the season - April 27 at San Diego - Fields allowed 3H/1ER in the 7th, but the Astros won the game, anyway. From his next outing until the All-Star Break - 27 appearances - Fields threw 27.2IP, allowing just 14 hits and seven earned runs, with 37K:12BB. This was peak Good Bullpen.
And despite a hiccup in his first appearance after the All-Star Break (1IP, 3H/2ER) in a 7-6 loss to the Rangers (a one-run loss to the Rangers. You. Don't. Say.) on July 18, Fields threw in 14 games/12IP, allowing seven hits and two earned runs with 15K:2BB. So naturally the Astros sent Fields to Corpus following his August 19 appearance in which he recorded a win against the Rays.
Why was a reliever with a 2.20 ERA, a WHIP under 1.00 and an OPS-against of .516 sent to Corpus? Because he could be sent to Corpus. That August 19 game was a 13-inning affair, their 3rd extra-inning game in their previous five. The bullpen was taxed, the team needed pitching, and Fields had options left.
Things were not as good for Fields when he returned when the rosters expanded in September. In his first game back he allowed 3H/3ER in an 8-3 loss to the Mariners. Five days later, on September 7, he gave up 4H/4ER in 0.1IP in the 10-9 loss at Oakland. In eleven September appearances, Fields allowed at least one hit in eight of them and at least a baserunner in nine. In 43 appearances prior to September, Fields allowed at least one baserunner in just 24.
Fields generated lots of pop-ups, but not much in the way of home runs. His GB/FB ratio was 0.72, 3rd-lowest on a team that values extreme groundball rates, but he had a team-best 3.5% HR/FB ratio, while at the same time having a team-high 45.1% of balls hit up the middle of the field.
At 7.9 wFB, Fields threw the 3rd-most valuable fastball on the team in 2015, behind Keuchel (15.5 wFB), and Will Harris (12.5 FB). Only Velasquez (94.6mph) and McCullers (94.5mph) threw their fastball at a higher average velocity than Fields' 94.3mph in 2015. The next-highest fastball velocity was Will Harris at 91.8mph - 2.5mph slower than Fields. Fields throws hard in a bullpen that doesn't really throw hard.
I don't see much in the way of challengers for Fields. He throws an elite pitch and is extremely effective until he briefly is not. Fields also throws hard, which is unique for the current version of the Astros' bullpen. There is evidence that he was simply unlucky, and he's gotten better with each season he's been with the Astros. He's under team control for three more seasons and is still only 30 years old.
FanGraphs: Josh Fields and the Value of Faith and Positive Thinking (September 2015)