2020 KC Royals season preview: Trevor Rosenthal

The KC Royals signed a former National League reliever this winter and hope he regains the form that made him one of baseball’s best closers. He has a long way to go to make that happen in 2020.

Welcome back to the Kings of Kauffman 2020 KC Royals Preseason Player Previews. Our writers are breaking down 30 players throughout the next month; we’ll analyze how each fared last season, discuss projections for 2020, and offer commentary about both. Up for today is relief pitcher Trevor Rosenthal.

The KC Royals have become Trevor Rosenthal‘s baseball lifeline, providers of perhaps his last chance to recapture the form that just a few years ago made him one of the best closers in the game.

Signed to a minor league contract that will pay him at least $2 million if he makes good on KC’s invitation to Spring Training and lands a Royal trip to the majors, Rosenthal is coming off a 2019 season best termed horrific. Cast off by the St. Louis Cardinals after two disappointing seasons and another lost to recovery from surgery, Rosenthal first pitched 6.1 innings for Washington and gave up 16 earned runs for a 22.74 ERA; in that span, he also posted an astronomical 21.3 BB9.

Detroit then took a chance on Rosenthal after the Nationals released him, but he fared barely better, posting a 7.00 ERA with a 1.556 WHIP and 11 BB9. Only his season strikeout rate of 10 per nine innings provided any reminder of how good Rosenthal had once been.

Indeed, his 2019 performance stands in stark contrast to his first three St. Louis seasons. In 2013, his rookie campaign, Rosenthal struck out almost 13 batters per nine innings and had a 2.73 ERA and 1.91 FIP. He saved 45 games the next season with an 11.1 SO9, then saved 48 games–still the Cardinals’ single-season record–and had a 2.10 ERA and 10.9 SO9 in 2015.

Drastic decline followed in 2016 and ’17. Rosenthal saved only 25 games across those campaigns, his ERA jumped to 4.46 in ’16, and previously moderate control issues increased. A 2017 UCL issue led to corrective surgery and caused him to miss the entire ’18 season after the Cards released him in November 2017.

2020 Baseball-Reference & Fangraphs projections. Rosenthal’s recent history suggests a bleak future, especially considering a disastrous 2019 marred by excessive walks and an unfortunate tendency to give up runs. Projections by both Baseball-Reference and Fangraphs are pessimistic for 2020: Fangraphs predicts Rosenthal will pitch only 15 games, go 1-1 with a 4.31 ERA  and walk over five batters per nine innings; Baseball-Reference is similar, projecting him at 2-2 with a 5.45 ERA and slightly less than five walks per nine.

How will Rosenthal actually perform? While these projections are consistent with Rosenthal’s most recent metrics, their necessary reliance on those metrics doesn’t take into account a potentially positive consequence of him joining the KC Royals–a reunion with new manager Mike Matheny, hired by the club to succeed the retired Ned Yost. It was with Matheny as his manager that Rosenthal enjoyed the best three seasons of his career–2013, ’14 and ’15–and working again with Matheny certainly can’t hurt the prospects for his return to top form.

And pitching coach Cal Eldred is also familiar with Rosenthal from his own days with the Cards.

Positive, too, is that Rosenthal, a career fireballer with a still powerful fastball, is a strikeout artist with a 12.0 career SO9; even in the dark days of his 2019 season, he struck out 10 per nine innings and in 2016 and ’17, prelude campaigns to his horrendous 2019, he had SO9’s of 12.5 and 14.3. It is the control problems that plague him.

How will Rosenthal fare in 2020? Perhaps better, because he has nowhere to go but up; 2019 was rock bottom compared to his best, most successful St. Louis years. If he can harness his control problems–or at least reduce them–he stands to break spring camp with the Royals and improve his performance. A late-inning relief role is realistic if he can cut down his walks, a closer role possible when the Royals make the inevitable midseason trade of Ian Kennedy.

But a Rosenthal rejuvenation is dependent on better control, and he’s never been pinpoint in that key component of his game. His command must improve. As discussed previously in this space, the Royals’ spotty history with repairing broken veteran pitchers doesn’t bode well for a successful end to what with Rosenthal is another of General Manager Dayton Moore’s pitching reclamation projects. It’s all a matter of control and command for Rosenthal.

The KC Royals are taking yet another chance that a veteran pitcher can recapture his past. Trevor Rosenthal will do so, and become a productive member of the club’s 2020 bullpen, if he can control his control. If not, his stay with the Royals will be short.