Mariners Edwin Diaz: Top-5 Fantasy RP in 2017?

Edwin Diaz stepped up for the Mariners last season, locking down the closer role by the end of the season. Due to his success, could he now become a top-5 fantasy RP in 2017?

Relievers are usually one of the hardest positions to predict in fantasy baseball. While there are some heavyweights who are near shoe-ins for success, there are also wildcards that can join the elites. One of those potential wildcards is Mariners’ RP, Edwin Diaz.

Edwin Diaz has always possessed an electric arm and entered the 2016 season as the Marines top pitching prospect. He found relative success in the minors, career 3.57 ERA,  but it seemed as though he was plateauing as a fringe starter.  Seattle made the move to start bringing Diaz more out of the bullpen during his time at AA, and the positive results were immediate.

Diaz would not make his MLB debut until June, and during that time the Mariners were trying to handle Steve Cishek’s woes. The decision to promote Diaz to the majors was an easy call as the Mariners were fighting for a playoff spot, and he offered the best chance for Seattle to somehow find an alternative out of the bullpen late in games.

He would finish the year with an 18 SV/2.79 ERA/1.16 WHIP/88 K line over 51 innings. The first things that jump out are the K. His 88 K over 51 IP gives him an eye-popping 15.3 SO/9. That ranks easily among the best in the league and a ratio that should make owners salivate.

Edwin Diaz features a two-pitch arsenal that gives batters fits. His fastball is clocked in at averaging 98 mph, but his put away pitch is a wipeout 87 mph slider. He delivery also plays into his deception as well, as hides the ball well, and has a short arm action.

While his fastball can beat hitters on velocity alone, it does lack the late life that some RP have. He forced a 15% Whiff rate with his fastball alone, a solid K clip nonetheless. On the other hand, his slider is just downright filthy. It was easily his most used pitch and rightfully so, as it forced a 33% Whiff rate.

After finally being placed in the closing role, Diaz managed to go 18 for 21 in SV chances in 2016. A solid SV rate for the 22-year-old first-time closer. The Mariners as a team had 56 SV opportunities last season. Seattle’s offense still looks potent, and the rotation still has enough talent to come close to offering the same number of chances.

Diaz has the arsenal, situation, and beneficial home ballpark to continue to climb the ranks. His Whiff rates do not lie, and he is still only getting better as he develops. Look for him to surpass the 100 K mark in 2016, and flirt with 30+ SV. Thus making him one of the best fantasy RP targets this spring.