Who the odd man out in the Phillies outfield should be | David Murphy

There will be an odd man out in the Phillies outfield. That much is clear, now that Carlos Santana is in the fold and Rhys Hoskins is the starting leftfielder. Whether it happens via trade or via injury or via platoon is a question that will animate much of the next three months of the Phillies offseason. One of the few things we know is that the rules of the game are unlikely to change before opening day to allow Gabe Kapler to fill out a lineup card that includes all of Aaron Altherr, Nick Williams and Odubel Herrera. Also, Hoskins will not be the odd man out. We know that. I think.

Beyond all of that lies a vast range of potential outcomes that depend on a set of variables that are difficult to consider without also considering their dependence on each other. For instance, consider the situation in center field, which, is the most logical place to start, given the specialized skill set its defense requires. My sense is that the consensus opinion of the fan base holds Odubel Herrera to be the most expendable hitter of the bunch. Philadelphia is a town that would rather you drop your bat at your feet like a gentleman and move from point A to point B with maximum effort and attention, two things Herrera sometimes forgets to do. Plus,  the memory of his rough first half lingers like the morning after a night in a smoky bar.

Problem is, Herrera plays a position that is less easier staffed than those on either side of him. Hoskins does not play center field. Williams played 111 innings there last season, but that was more as a least worst option while the Phillies struggled with injuries. It's difficult to imagine Matt Klentak and Co. considering Williams as anything more than an emergency fill-in. The bigger question is how they feel about what they saw out of Altherr last season in his 101 innings in center. The fact that the metrics paint a generally positive picture of Herrera's defense at the position combined with the fact that Altherr spent most of September playing the corners could offer a pretty good hint at their true feelings. The modern baseball establishment generally agrees that center field is not the position where you want to sacrifice defense, and Herrera has swung an above-average bat for the position for three straight years.

If not Altherr, the only potentially imminent solution to replace Herrera in center field is 2017 first-round draft pick Adam Haseley, who played there exclusively this summer after the Phillies selected him at No. 8 overall out of Virginia. On the one hand, he was projected as a fast riser, and he hit a respectable .284/.357/.405 with a strikeout-to-walk ratio of 2-to-1 in 58 games in the Gulf Coast, New York-Penn and South Atlantic Leagues. But that's an awfully skinny resume to pencil into your lineup as a replacement for a 26-year-old who has hit .288/.344/.430 in 444 career games against big-league pitching. As for Mickey Moniak, the No. 1 overall pick in the 2016 draft, he is 20 years old and posted a dismal .625 OPS at low-A Lakewood last season.

Really, the only way the net benefit of trading Herrera could exceed that of trading somebody else is if Altherr can play 140 games in center field at his current offensive production without being a defensive liability.

And that brings us to our second variable: reliability.

In the first three years of his career, Herrera has averaged 148 games, 585 plate appearances, and a .774 OPS that puts him as an above-average big-league hitter. In Altherr's first three years, he has averaged 68 games, 267 plate appearances, and a .775 OPS. Altherr has power potential that Herrera can't match, but he is one year older and a frequent resident on the disabled list who has never played more than 107 games in a season.

Williams has even less of a track record. He is coming off a rookie season in which he hit .288/.338/.473 with 12 home runs in 343 plate appearances. His OPS+ of 113 ranked in the top 35 percent of outfielders with at least 325 plate appearances (Altherr's 124 OPS+ ranked in the top 18 percent). There are some concerns: He struck out every 3.2 at bats, ranking him in the bottom 14 percent of hitters with at least 325 PAs, and his walk rate ranked in similar territory. But the reasons for hope are there, too. He will be just 24 years old next season, he held his own against lefties, relative to a lot of rookies, and he showed the power potential that has been a part of his scouting report since the Phillies acquired him in the Cole Hamels trade.

One thing worth mentioning is that all these factors play a similar role in the trade value each player has. If we are operating on the assumption that a trade is the most likely end game, then the player who ends up moving will be the one who offers the greatest surplus between "What can we get in return for him?" and "What do we lose in giving him up?" If the Pirates are willing to build a package for Gerrit Cole around Herrera but not Altherr, that factors rather significantly into the calculus.

Therein lies the chief difficulty in an exercise such as this. A lot depends on the internal opinions of other teams. My sense, though, is that Williams is most likely the player who will offer the Phillies the most beneficial split between his likely future value to them versus his trade value to other teams. Altherr's limited track record relative to his age and his history of injuries could mitigate his trade value in a way that makes it a better bet for the Phillies to hold onto him and hope that he reaches his ceiling on their watch. On the flip side, Herrera's three straight seasons of above-average offensive production at a premium defensive position and his ultra-team-friendly contract should make him cost prohibitive for most teams. Even for a pitcher like Cole, does it make sense to trade six seasons of above-average offense in center field for two seasons of top-of-the-rotation pitching, especially when you consider that the Phillies could be paying him just 60-70 percent of his market value over the final few years of his deal? (He has signed for less than $9 million per year over the next six years.) The only way it makes sense is if he suffers a significant drop-off from his production over the last few years.

Last week, the Phillies insisted that they are comfortable with the thought of entering the season with four young outfielders for three spots. Retaining all four would not only allow Kapler to mix and match based on pitching matchups, but also would constitute something of hedge against the uncertainty inherent in any young group. Instead of hoping 100 percent of your young outfielders establish themselves as viable first-division regulars, you could go 3 for 4. In the meantime, there are enough games that four players could average 121 starts in the outfield, which would put them close to 500 plate appearances even before considering days off for Santana at first base, and 10 games that will enable them to use a DH.

Last year, three teams had four outfielders finish with at least 400 plate appearances, including the NL Central-champion Cubs. In fact, all three teams finished at better than .500 (the Cardinals and Brewers were the others).

"The game is evolving," Klentak said. "We are moving past the days where it's a cookie-cutter lineup — the same eight guys in the lineup every day, hitting in the same spot in the lineup, playing the same position for 160 games a year."

That's a better scenario than giving one of the four away for nothing. But the best scenario is parlaying one of them into a starter capable of pitching 180-200 innings behind Aaron Nola. Toward that end, Williams might be the guy who makes the most sense to move.