While speaking with Access, the F9 actor, 53, opened up about Walker's legacy and how he looked up to the late star when he became a parent in real life, even if their characters in the Fast and Furious films had a differing mentorship dynamic onscreen.
"I was always the big brother on set, would protect anybody and ride for anybody. They may have looked up to me on set from the very beginning, but I hadn't been a father, and Pablo had," said Diesel of Walker, who was dad to daughter Meadow Walker, now 22.
"So I leaned on him when I transitioned [to fatherhood]," continued Diesel. "He was my rock. He was the one that said- the irony is what the roles that we had and the scenes that we had that discussed fatherhood in Fast Five and throughout the franchise in real life were reversed. To the point where, as you know, my youngest child, when I was in the delivery room and writing down her name, even my mom to this day says, 'Pablo was in the room with you.' And that's why I wrote Pauline."
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Vin Diesel and Paul Walker in March 2009
Meadow Walker/Instagram Meadow Walker and Vin Diesel with his daughter Similce
Walker died in a single-car crash in November 2013 at age 40.
Meadow remembered her dad on the seventh anniversary of his death this past November, sharing a throwback of the two of them napping together when she was a child. "A silly day to remember in sadness," she wrote in the caption at the time. "Today's a celebration of the love and happiness you brought to the world. Here's a photo of my best bud & I napping."
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"He loved being a dad. He was so proud of [Meadow]," Walker's brother Cody told PEOPLE in 2018, while Paul's father Paul Walker III said of his son, "No father loved a child more than he did Meadow."
Diesel has also treated Meadow like family over the years. "I could say that I am so proud of the person you are becoming ... but the truth is I have always been proud of you," he wrote on Instagram in 2019, celebrating her 21st birthday.
"Happy Birthday Meadow!" he continued in the caption. "I know it's your 21st and you wanted to go big in Japan, but the family has a cake waiting for you when you get home, so hurry. Love you kid. Uncle Vin."