NEW YORK (CBSNewYork) — It has been a heartbreaking week for Mark Sanchez.

On Monday, the Dallas Cowboys backup quarterback served as a pallbearer at the funeral of Joe McKnight, his former USC and Jets teammate who was shot dead in a road rage incident.

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Also Monday, Konrad Reuland, who was Sanchez’s childhood friend and also a Jets teammate, died after suffering a brain aneurysm.

Sanchez wrote a heartfelt note on Instagram on Tuesday about his relationship with Reuland.

“Losing you is like losing a brother,” he wrote. “Our friendship started when we were kids playing travel basketball for the Piranhas with our dads coaching us. We worked together and realized our dream of being professional athletes. And there we were, suiting up as teammates for the NY Jets in the NFL!!! It really was something unique and special to share together. You will always be in my heart. Rest easy my friend, until I see you again.”

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Sanchez and Reuland played together at Mission Viejo High School in California.