The Seattle Mariners will be relying heavily on their bullpen in 2018. On paper, the unit looks to be a real strength, and perhaps no bullpen member is more valuable than closer Edwin Diaz.

Diaz will enter 2018 in his second full season as the Mariners closer. Fans should recognize the soon to be 24 year old’s electric stuff when he is on. The sizzling 97 mph heater with arm-side run that touches 101. The wipe out slider that destroys the will of right-handed hitters.

When he is on, Edwin Diaz is flat-out unhittable. But of course, there is the other end of the spectrum. The times when Diaz could not find the strike zone if his life depended on it. So, what Diaz will we see in 2018?

Probably the same blend we have witnessed over the past 2 seasons. Diaz boast a 13.54 K/9 with a 3.59 BB/9. So even an “up and down” Diaz is still better than almost any other reliever in baseball.

However, this season, the bullpen will need to be damn near flawless. While the Mariners do have a plethora of options to replace Diaz if needed, his return to elite status is still necessary for Seattle. Diaz saw his FIP jump from 2.04 2016 to 4.02 in 2017.

Diaz’s K/9 dropped from 15.33 to 12.14 and his BB/9 jumped from 2.61 in 2016 to 4.36 last season. He also saw his ground ball rate dropped from 46.8% to 39.1% as well. All paint a troubling sign for Edwin Diaz, but how do we see his 2018 playing out?

Sodo Mojo’s 2018 Projections for Edwin Diaz: 65 IP, 46 hits, 22 runs, 9 HR, 90 K, 26 BB, 38 saves, 3.05 ERA, 1.11 WHIP

As you can see, we project a good, but not elite Diaz. The K/9 stays at 12.5, and the ERA falls right in line with his career average. Our 3.39 FIP projection shows modest improvement for Diaz this season.

As mentioned earlier, the Mariners should have no shortage of options should Diaz falter. Juan Nicasio, David Phelps, Nick Vincent could all fill in if needed. However, if the Mariners need to make a drastic change to its bullpen, it could be a long season for Seattle.