The Mariners announced a series of roster moves today, reinstating right-hander Bryan Woo from the injured list and signing righty Luke Weaver to a major league deal. To open two active roster spots, they optioned righties Eduard Bazardo and Darren McCaughan. To open a 40-man spot for Weaver, righty Emerson Hancock has been transferred to the 60-day injured list.
It’s a belated birthday present for Weaver, who just turned 30 years old yesterday. He was recently released by the Reds, who had signed him to a one-year, $2MM deal in the offseason. Unfortunately, his 21 starts for Cincinnati resulted in him allowing 6.87 earned runs per nine innings. His 7.6% walk rate was solid but he only struck out 19% of batters faced. Home runs were a particular problem as he allowed 24 balls to sail over the fence in that time, easily a career high for him.
The Mariners were planning to utilize a six-man rotation when Woo returned from the injured list, joining Hancock, Luis Castillo, George Kirby, Logan Gilbert and Bryce Miller, but Hancock’s injury threw a wrench in those plans. He landed on the injured list yesterday due to a shoulder strain and it seems the club isn’t expecting him back soon. Today’s transfer makes him officially ineligible to return until the middle of October. His season is now effectively over unless the club goes on a World Series run and he gets healthy enough in the next two months to put himself in position to rejoin the roster. Daniel Kramer of MLB.com reports that his recovery will take at least four to six weeks.
The club could simply go with a five-man rotation, though there are reasons why they might still prefer six. Both Miller and Woo are rookies who are pushing towards uncharted territory in terms of innings pitched in a season. Last year was Miller’s first full professional season and he was able to toss 133 2/3 frames. This year, between the majors and minors, he’s up to 117 1/3 already. Woo, meanwhile, tossed 67 2/3 last year and is already up to 99 innings this year between Double-A and the majors. Kirby was a rookie last year and logged 130 major league innings plus another 26 2/3 in the minors, and is at 150 2/3 this year.
Going with a six-man rotation would soften some of the workload concerns and the potential for fatigue down the stretch. Perhaps that is why they have brought Weaver aboard. Though his results haven’t been good this year, a change of venue would likely help him to some degree. Looking at Statcast’s park factors, the Mariners have one of the more pitching-friendly home parks while the Reds are on the other end of the spectrum, especially when it comes to home runs.
It’s also possible that the Mariners are planning to implement Weaver out of the bullpen, a role in which he’s showed some encouraging signs in the past. With the Diamondbacks and Royals last year, he had an ERA of 6.56 overall, but that included one start in which he allowed nine earned runs. As a reliever, he had a 4.78 ERA and may have deserved even better. He had a 21.7% strikeout rate, 7.9% walk rate, 40.4% ground ball rate and didn’t surrender a home run at all. But a .404 batting average on balls in play and 64.9% strand rate pushed some extra runs across the plate, with his 2.46 FIP suggesting he was perhaps better than his ERA would indicate.
Regardless of his role, it’s a low-risk move for the M’s financially. Since the Reds released Weaver, they remain on the hook for what’s left of his $2MM salary, while the Mariners will only have to pay him the prorated league minimum for any time spent on the roster. That amount will be subtracted from what the Reds pay.