The 24-year-old Ceciliani was hitting .336/.381/.584 in 37 games with triple-A Las Vegas this year in his first exposure to the minors' highest level. He was doing so with ordinary walk (7.9%) and strikeout (19.8%) rates but very high numbers on contact (.384 BABIP) and a .248 isolated slugging percentage.
Ceciliani can thank the Pacific Coast League for his impressive-looking numbers to start the year. Both of these last two marks are out of line with his previous minor league career, particularly the isolated slugging. Never in his minor league career has Ceciliani had a BABIP this high in any full season league, although he came close with a .375 mark in advanced-A. His isolated slugging mark is even more anamolous. Throughout his minor league career, he had run isolated slugging numbers between .100 and .130. Now, it's nearly twice that mark in Vegas. This is real in the sense that it has happened, but it does not reflect his new skill level. A picture will help.
Meanwhile, up in the big leagues, Captain Kirk is 3-for-38 with two doubles for a .079 batting average and has struck out in over 42% of his plate appearances. He has been really, really bad. However, this comes on the heels of a perfectly acceptable .259/.346/.482 performance in 130 plate appearances off the bench in 2014, mostly against righties. Simply, leaving aside recency bias issues, the 140 plate appearances in 2014 should carry more weight than the 40 plate appearances this year.
So, what does Ceciliani bring compared to Nieuwenhuis, who has gotten off to a brutal start in 2015? Both hit left-handed. Both can play centerfield. However, Nieuwenhuis is bigger, runs better and has a better arm. While no one will confuse Nieuwenhuis with the resident Gold Glover starting in center, he is a better defender than Ceciliani. At sea-level, Nieuwenhuis has shown more power with the plate. When you account for the two levels at which Nieuwenhuis and Ceciliani have both played in the minors, Nieuwenhuis has outperformed Ceciliani at every step except AAA, where Ceciliani has been for barely more than a month. The chart below compares the two players' offensive production, as measured by wRC+ for each full-season level. wRC+ accounts for league level, but its adjustment for the PCL does not seem strong enough so to compensate, Nieuwenhuis' triple-A experience as a member of the Buffalo Bisons is excluded.
Ceciliani probably has one advantage at the plate in a shorter swing. In triple-A, Nieuwenhuis struck out in over 25% of his plate appearances. Ceciliani, in his 126 plate appearances in 2015, has whiffed 20% of the time. It's early yet, and generally even these reliable strikeout numbers do not stabilize until at least 150 plate appearances. How real is this? In double-A, their strikeout rates were very close: 21.5% for Nieuwenhuis to 20.7% for Ceciliani.
There's no question that Ceciliani has had a more productive beginning to the 2015 season than Nieuwenhuis, but he did so at triple-A, in the Pacific Coast League while Nieuwenhuis was facing tougher pitching in a tougher environment. To believe that Ceciliani is a better player requires either a lot more faith in the numbers produced by a player in one month of baseball deserve, or a leap to the idea that this month's worth of production reflects an underlying shift in the relative value of each player's performance.
At the back end of a roster, there will always be a high level of variance in players' performance relative to their true level of ability because each guy gets relatively few plate appearances or innings to show what he is worth. And maybe there is something to riding the hot hand, neither player has done enough in 2015 to really shift what should be expected from each moving forward. In practice, the two players' projections should have been similar and neither would have earned enough plate appearances to dramatically change the 2015 Mets' fortunes.
Instead, the much more important additions for the Mets in the near term involve bringing back David Wright and Travis d'Arnaud, healthy and productive .