Why Starting Pitching Has Been Mariners' Biggest Strength, But Also Their Biggest Need
There is no denying the Mariners have had excellent starting pitching so far this season. Before Wednesday's doubleheader against the Nationals, which saw Erik Swanson start game two as an opener for Tommy Milone, Seattle has barely had to adjust from its initial rotation.
So how could this be the team's biggest need? Let's take a look.
Across Major League Baseball, the Mariners rank fifth overall in ERA at a 3.56 clip, ranking behind the Dodgers, Astros, Yankees and Rays. But while that is certainly impressive, perhaps the rotation's greatest feat is instead the amount of innings it has logged.
Led by the likes of Robbie Ray (110.1 innings pitched) and Logan Gilbert (106), Seattle ranks third in MLB in innings pitched, coming in at a mark of 493 innings. This falls just 12 innings off the leading pace.
The starters have been fantastic, with a mix of reliable veterans and rising young stars. So why would they need to add to this group? Who would they replace?
The first and most obvious reason is health. This group has been remarkably healthy, but we know from past seasons that you need starting pitching depth. If any one of these guys were to hit the injured list, Seattle would largely be relying on Triple-A depth that is largely unproven.
The second most obvious reason is that George Kirby is going to hit his innings limit at some point. Last week, Kirby was optioned down to Tacoma to manage his workload. Recently on Ryan Divish's Extra Innings Podcast, it was revealed that Kirby's innings limit will be somewhere around 120.
It is unclear whether or not the Mariners will take into account innings thrown at Arkansas early in the year, but this innings limit will approach rapidly either way. He has thrown 64.1 innings for Seattle and over 80 if you add in his time in the minors.
Another positive of adding a starter is the aid it provides to the bullpen. So far this year, the Mariners have had one of the best bullpens in the league, and it has been especially effective since the rotation took off.
The more innings the starters throw, the less usage your bullpen gets and the more fresh you become. This is why it is important to add starting pitching, especially the kind that can pitch near the top of a rotation.
The Mariners have several arms that can pitch near the middle or the top of a rotation, but not many besides Ray and Gilbert have shown they are capable of doing so for a full season's worth of work.
Seattle must add someone who can throw deep into games and compete to throw in the second or third game of a playoff series. Some names that fit this bill and are expected to be available include: Frankie Montas, Tyler Mahle and Luis Castillo.
This is why general manager Jerry Dipoto has built a farm system, not only to have those players contribute in Seattle but to acquire proven big league talent. He has shown the ability to get creative in the past, and we should expect to see that again over the coming weeks.
