Interesting set up and very creative.
Though, Flag/Traffic light indicator isn't all that useful at the moment and doesn't convey any meaningful story.
If you want to compare apples to apples... you'd need to adjust some of the stats based on # of Games played or # of times at bat.
ex: Castellanos with 157 GP and 185 H shouldn't be using same indicator range as Cabrera with 38 GP and 40 H.
Few other suggestions:
1. Add control to show aggregated data for team and also to compare 1 player to another.
2. May be have league avg/median for each stat to show where each player stands in larger picture.
3. Show top/bottom N players for each stat (or add control to retrieve that info).
4. Pitcher dash is bit too busy with color and not easy on the eye.
I assume this is for baseball enthusiast, so not a big deal, but I'd generally recommend adding glossary of terms for stats and abbreviations used.
I'd give this dashboard A grade, if the purpose is to show off your creativity and skill in Excel.
C grade, if the purpose is to use this dashboard is to convey a story based on data, or to be used as discovery tool.