Semien’s agency switch comes amid a breakout campaign for the 28-year-old, a valuable regular from 2015-18 who has found another gear this season. Acquired from the White Sox in a significant December 2014 trade, Semien entered this season as a lifetime .249/.310/.403 hitter with 9.7 fWAR in 2,637 plate appearances. Semien has since has slashed a career-best .276/.363/.480 with a personal-high 4.3 fWAR in 524 trips to the plate. He slugged a pair of home runs Monday, giving him 19 on the season and easily putting him on pace for the second 20-HR showing of his career.
Semien’s offensive strides have come thanks in part to improved plate discipline, as he has posted the top strikeout and walk percentages of his career (13.9 and 11.8, respectively). Meanwhile, Semien has also taken noticeable steps forward as a defender over the past couple seasons. He combined for minus-15 Defensive Runs Saved and a minus-9.7 Ultimate Zone Rating from 2016-17, but he’s now enjoying his second straight year in the pluses in those categories (13 DRS, 14.4 UZR since 2018).
The well-rounded Semien has emerged as arguably one of the premier middle infielders in baseball – all the more auspicious for a low-budget A’s team that’s not breaking the bank on him. Semien’s making a a team-friendly $5.9MM salary this season, but unfortunately for Oakland, his bargain days don’t look as if they’ll continue for much longer. Next year’s slated to be Semien’s last as an arbitration-eligible player, and though the Athletics have discussed an extension with him, nothing has come together yet.
[RELATED: MLBTR Agency Database]