Fitzgerald lost his former coach/mentor Dennis Green and his agent, Eugene Parker, within four months of each other.
Green died July 21 from cardiac arrest and Parker died March 31 after battling kidney cancer.
"It's been very difficult," Fitzgerald said. "Those two men are tremendous mentors for me. Coach Green gave me both jobs I've ever had in my life. All the ups and downs of going through my career, he's always been one that's always been there for me.
"Same with my agent, Eugene Parker. Met him when I was 19 years old and we grew together over the years. It's been really tough losing two people I hold in the highest regards."
Fitzgerald first met Green when he was 9 years old through Fitzgerald's father, Larry Fitzgerald Sr.
Fitzgerald Jr. became a ball boy for the Minnesota Vikings during Green's tenure there and then was drafted by the Green-coached Cardinals in 2004.
Parker helped negotiate each of Fitzgerald's four NFL contracts, as well as a restructured deal in 2014. Fitzgerald has earned about $129.3 million in his career, according to Spotrac research.