Here’s another data point pointing toward the idea that long slumps are due to injury. Jose Ramirez of the Guardians needs hand surgery:

There has been speculation as to how much that thumb impacted Ramírez down the stretch. Leading up to June 18, Ramirez was slashing .305/.397/.642 and posted a 188 wRC+ in 262 plate appearances, putting him firmly in the AL MVP conversation. He cooled down significantly after that, slashing .264/.329/.437 with 108 wRC+ in 423 plate appearances since returning the lineup on June 21.

CoveringTheCorner.com

The Guardians believe he will recover by spring training.