Just looked up some numbers for Bautista:
K rate
2015 - 15.9%
2016 - 19.9%
2017 - 24.8%
Walk rate
2015 - 16.5%
2016 - 16.8%
2017 - 12.2%
Contact %
2015 - 80.9%
2016 - 80.2%
2017 - 73.3%
Swinging strike %
2015 - 7.5%
2016 - 7.2%
2017 - 10.9%
Something definitely happened in 2017, either eye problems or he just lost enough bat speed that he can no longer catch up to fastballs.