Mariners Send Elias, Strickland to DC, Acquire LHPs Taylor Guilbeau, Aaron Fletcher and RHP Elvis Alvarado

The Mariners have elected to trade relievers Roenis Elias and Hunter Strickland to the Washington Nationals in exchange for Top 30 LHP Prospects Taylor Guilbeau and Aaron Fletcher. They also received RHP Elvis Alvarado in the Elias deal.

Guilbeau, 26, is unequivocally the anchor of this deal for Seattle. Ranked the 15th best prospect in the Nationals system by MLBPipeline.com, and 14th best by Baseball America, Guilbeau is a lefty-specialist coming out of the bullpen.

A two-pitch southpaw, Guilbeau has generally been regarded as a LOOGY specialist in the past, though his reverse splits this year suggest otherwise. He’s had a knack for stranding runners this season, holding opposing hitters to a .208 average with runners on.

Armed with a low-to-mid-90s fastball and plus slider, Guilbeau dominated the AA circuit this season to the tune of a 2.31 ERA with a minuscule 1.06 WHIP. Since being promoted to AAA Fresno, his performance hasn’t been quite as impressive, registering a 5.19 ERA in just over 7 innings of work.

Control has been an issue for the 2015 10th round pick in years past, though he’s improved in that area in 2019.

This being his fifth year in minor league ball, Guilbeau will be eligible for the Rule 5 draft come December, so Seattle may elect to add him to their 40-man roster on September 1st for a cup of coffee, if not sooner.

He’s tried to work in a developing changeup this season that still flashes below average. If the slider continues to improve, and the changeup develops into average, all while maintaining control, Guilbeau could profile as a Sean Doolittle type.

Fletcher, 23, is another Top 30 farmhand from the Nationals’ system, ranked 21st by MLBPipeline, and 19th by Baseball America. He profiles similarly to Guilbeau, though he provides a little more deception in his delivery.

Armed with a mid-90s fastball and similar slider, Fletcher absolutely dominated lower-level ball this year, posting a 1.50 ERA and 0.76 WHIP in 52 innings across A-Ball and High-A ball.

Since being promoted to AA Harrisburg, Fletcher hasn’t been quite as dominant, registering a 4.26 ERA in just over 6 innings of work.

The slider is the real prize when it comes to Fletcher’s arsenal. His funky delivery and natural deception makes the slider torture on left-handed hitters, while righties haven’t fared too well either. Lefties are posting a .173 average against the pitch this year, while righties are mowed down at a .170 clip.

A 14th round selection in the 2018 draft, Seattle can be patient in their development with the young southpaw. He’ll likely get plenty of seasoning in AA Arkansas this year, as well as in 2020. There’s no rush here.

Alvarado, 20, is a bit more of a lottery ticket. Not as decorated as Guilbeau or Fletcher, Alvarado signed as an international free agent out of Dominican Republic in 2016 for $700,000 — a high price tag. Originally signed as a big-bodied corner outfielder, Alvarado made the move to the bump in 2018 where he’s worked ever since. At 6-foot-4, 195lbs, he can really bring it on the mound.

An arsenal containing a mid-90s fastball and developing secondary pitches, Alvarado elected to move into a rotation spot for 2019, where he’s struggled thus far.

In 17 innings in the GCL, his 5.29 ERA and 1.76 WHIP won’t drop and jaws, but 24 strikeouts in that short sample size might. He’s really struggled with command and containing his stuff within the strikezone, but the power is there. He’s still working in the Gulf Coast League, and will likely be sent to the AZL to get more seasoning and experience for Seattle.

If Seattle elects to move him into a full-time bullpen role, he may see Everett this season.