Reid Detmers: Fantasy Baseball Bust Or Breakout Reliever In Waiting?

Despite a rocky start to his MLB career, Reid Detmers' recent flashes of dominance and lefty pedigree make him a deep-league stash candidate with sleeper upside as either a starter or future closer.

Los Angeles Angels reliever Reid Detmers (48) delivers a pitch during the seventh inning against the Seattle Mariners at T-Mobile Park. | Stephen Brashear-Imagn Images

The last two seasons by Reid Detmers have been painful to absorb in the fantasy market. He posted a 6.38 ERA and 1.56 WHIP over 115.2 innings despite showing strength in strikeouts (144). Home runs (18 over 87.1 innings) were a problem in 2024, and Detmers continues to issue too many walks (4.1 per nine innings – 3.9 in 2023).

His left arm was off to a reasonable start over his first nine appearances (2.57 ERA, 1.142 WHIP, and 14 strikeouts over 14.0 innings) this season. Some fantasy managers hoped his improvement would result in a return to the Angels’ starting rotation. Over his subsequent three appearances, Detmers was the worst pitcher in baseball (12 runs, 12 baserunners, and one home run over one-third of an inning). In two of the outings, he threw only 21 pitches to eight batters who all got hits.

At this point, Detmers was launched in AL-only formats (the only format where he made sense opening the year). Twenty-five games into 2025, he still has a 5.22 ERA and 1.534 WHIP over 29.1 innings with 37 strikeouts, which makes him easy to scroll over when searching for upside arms. 

For the fantasy sickos that believe in his arm, Detmers tends to be a weekly check-in to see if his arm is making any progress. Behind his losing curtain is an impressive run over 11.0 innings (no runs, 10 baserunners, and 18 strikeouts), leading to a win and two saves. So, is his progress real or a trap? Should Detmers be considered as a closer in waiting or a future starter? 

I was a Reid Detmers in the rotation guy, but he might just be a top 5 left-handed reliever in the sport.

Since May 9th , entering today, his ranks among LH RPs (min. 10 IP):
• 4th in ERA (0.64)
• 5th in FIP (1.57)
• 4th in WAR (0.6)
• 4th in K% (37.5%)
• 1st in WPA (1.42)

— BTH (@BeyondTheHalo) June 11, 2025

Fantasy Baseball Pitcher Historical Analysis

Back in 2006, I had a $5,000 team in the high-stakes market that fell to last in ERA and WHIP in late June. My pitching staff was a disaster, but my offense ranked well. I scoured the free-agent pool looking for a buy-and-hold to help my team. Somehow, I landed on Rich Hill.

In 2005, the Cubs gave him 23.2 innings of experience, but he allowed 24 runs, 25 hits, three home runs, and 17 walks over 23.2 innings with 21 strikeouts. Chicago called Hill up for four starts in May the following season, leading to fantasy misery (20 runs, 23 hits, five home runs, and 11 strikeouts over 19.1 innings).

Meanwhile, between 2005 and 2006, in the minors, Hill went 18-5 with a 2.65 ERA, 0.95 WHIP, and 329 strikeouts over 230.2 innings, earning him the stamp of the pitcher I wanted to roster to save my fantasy pitching staffs.

The Cubs call up Hill in late July, and he proceeds to allow four runs, nine baserunners, and one home run over 3.1 innings with one strikeout. Do I dump or do I hold? Over his final 12 starts, he went 6-3 with a 2.58 ERA, 0.978 WHIP, and 78 strikeouts. 

As for my $5,000 donation fantasy team, by the end of the season, I moved to midpack in ERA and WHIP while also gaining points in wins and strikeouts. I fell one strikeout shy of winning the league with 117 points in a 15-team league. 

In 1984, Rick Sutcliffe had a brutal 12-start run from April 18th to June 12th (6.23 ERA, 1.832 WHIP, and 45 strikeouts over 69.1 innings) with the Cleveland Indians. The Chicago Cubs acquired over the following week. Over his final 20 starts, he went 16-1 with a 2.69 ERA, 1.078 WHIP, and 155 strikeouts over 150.1 innings. Sutcliffe had five impact strikeout games (14, 10, 11, 15, and 12) over this span.

Is Reid Detmers A Fantasy Baseball Waiver Wire Gem?

Major league and fantasy teams should always have their eye open for talented players who are underperforming their potential. Detmers will look like fantasy roadkill to most game managers, but he has the left arm to rise from the ashes. Ideally, I’d like him to get traded to a contender that has the coaching staff to unlock pitching shortfalls. 

At the very least, Detmers is an arm to follow in all formats, in case he earns a starting job with elite success. He could earn helpful fantasy value closing games.

Randy Johnson was traded in-season to Seattle when he was 25. Over his first 33 games in the majors, he has a 4.48 ERA, 1.463 WHIP, and 155 strikeouts over 186.2 innings. Johnson went on to win 293 more games with a 3.24 ERA, 1.157 WHIP, and 4,720 strikeouts over 3,948.2 innings.

After the 2011 season, Andrew Miller was demoted from starting pitcher to the bullpen for the Red Sox. He opened up his major league career with a 5.79 ERA, 1.750 WHIP, and 288 strikeouts over 359.1 innings. Over the next six seasons, Miller went 26-15 with a 2.01 ERA, 0.892 WHIP, and 520 strikeouts over 332.0 innings with 51 saves. His career turned around at age 27.

Both of these examples are left-handed pitchers who started their professional careers with command issues. Detmers threw more strikes in college and in 2019 in the minors.