Complex sentence: This hit also served as the first of two concussions that Savard would receive in a 10-month span, the latter of which would result in his unofficial retirement due to post-concussion syndrome.
Split into simpler sentences: This hit also served as the first of two that Savard would receive in a 10-month span. Both resulting in concussion, and the latter resulting in his unofficial retirement due to post-concussion syndrome.