Drayer: Why Mariners will utilize 6-man rotation when Woo returns

“Who gets sent down when X comes off the IL?” is one of the questions I am asked most often. The answer is usually wait and see. Things happen. Often, particularly in the case of a pitcher, a new need will arise before that player is activated and the player that was called up stays. In the case of what happens when Bryan Woo returns from the IL, the answer has been given. The Seattle Mariners will keep ’em all as the plan all along had been to go to a six-man rotation.

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“We were intending after these off days to go to a six-man rotation for a period of time, which would help us to manage the innings for our young starters coming down that last month and a half of the season. And we still would like to do that,” Jerry Dipoto said on his weekly show on Seattle Sports.

The original plan was to bring Emerson Hancock up the this week, but Woo reporting soreness after his bullpen in Anaheim moved that timeline up. Woo is eligible to come off the injured list on Aug. 20. Now that he is up and has made his debut, Hancock will stay for the time being.

“We will look at what happens the next couple of weeks with Emerson in the rotation,” said Dipoto. “Our goal was to manage innings for those last six weeks anyway, and that’s one way we can do it.”

Bryce Miller is tracking to exceed his innings total last year by about 20 innings. That’s nothing out of the ordinary in terms of numbers, but the intensity is a different matter and that is certainly taken into consideration.

Woo is another story.

Coming off elbow surgery, he threw just 57 innings in 2022, and a total of just 118 in college and summer league ball. At 99 innings split between Double-A and the big leagues this year, it is easy to see how this could be a concern.

Dipoto’s preference in recent years has been to find ways to get young pitchers through a full big league season rather than to shut them down when they hit an innings limit.

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The innings limit itself seems to be a thing of the past. Gone are the days of rule of thumb year-to-year innings increase limits. With the ability to monitor pitchers like never before with not just eyes but technology, they have better ways to know how a pitcher is holding up. The Mariners will stick with that goal of getting Miller and Woo to the end of the season, and hopefully beyond using the six-man rotation.

The beyond part is important for all the starters. While the argument against a six-man rotation is why would you want fewer starts from your top arms, if you are looking at an extended season, that brief break could benefit them as well.

The Houston Astros, who prepare each year to have an extra month of throwing in the postseason, last year went briefly with the six-man rotation in hopes it would benefit their starters later. Both Logan Gilbert and Luis Castillo have put up better numbers on extra rest this season, with Gilbert’s four vs five days rest strikeout-to walk rate beong 5.44 compared to 7.38 and OPS against .717 compared to .567. For Castillo, his strikeout-to-walk rate difference is 4.19 to 4.92 and OPS mark .683 to .639. Their numbers with six days rest are not quite as strong, but still better than the regular four.

George Kirby has been a bit of a different story with a 12.75 strikeout-to-walk rate and 671 opponent OPS on regular rest with a 7.86 and .493 on five days.

The last concern would be the bullpen. With no more than 13 pitchers allowed on the roster, if a starter is added, one would have to be subtracted. Ideally, with the extra rest, starters go a bit longer in a six-man rotation.

Regardless, this year and last there has always been an arm in the pen who gets far less use than the others. Think Tayler Saucedo when he first came up and Devin Sweet more recently. The reason? They like to hold an arm back in case there are extra innings. The Mariners can afford to lose that last reliever for a short period and if the ‘pen is taxed, they can always call up another. For the short-term, this should be manageable.

If we do indeed see the six-man rotation, the timing will be good with 16 of their next 19 games coming against teams that are last or second-to -last place in their division with just two off days in that time. What follows will be a juggernaut of a finish to the regular season with games against the Dodgers, Astros and Rangers (seven).

While this move which is expected to be temporary is for the young pitchers, it should benefit all the starters, especially if there are extra innings to be thrown after the regular season.

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