Gunnar Henderson is a rookie this year by the grace of MLB’s formula, and that works to the advantage of Elias’s rating.
Henderson got 132 plate appearances in 2022; MLB rookie eligibility rules set a cap of 130 at-bats. But since Henderson walked in 16 of those 2022 appearances, he retains his rookie eligibility by the margin of 14 official at-bats.
There are those in Baltimore, and they are numerous, who think that margin will enable Henderson to come away with the Rookie of the Year Award. His .241 average doesn’t make a compelling case, but he’s added enough power to produce a +1.0 WAA. That at least makes him easily the most valuable rookie in Baltimore.
Henderson is one of seven rookies Elias has called on to varying degrees in the season’s first half. None of the others has produced a positive WAA for the home team.
Aside from Henderson, pitcher Grayson Rodriguez, a 2018 first-round pick who debuted April 5, is the most noticed. Over the course of the next six weeks, Rodriguez made 10 rotation starts, never surviving into the sixth inning and getting slammed for 38 run in 45 innings, all but one of them earned.
By late May, Rodriguez was back in Triple-A trying to work out the bugs that had led to his 7.35 ERA and -1.3 WAA.
The rest of the 2023 rookie class is a roster of wannabes. There are five (pitchers Logan Gillespie and D.L. Hall and position players Jordan Westburg, Kyle Stowers and Joey Ortiz) and all but Westburg have been sent back down.
Called up just last week, Westburg has debuted with five hits in his first 16 at-bats, a .316 average.