It comes after a very public feud between the two Hollywood heavyweights.
In an Instagram post, Vin said The Rock has "a very important role to play", adding that his character Hobbs could not be played by anyone else.
"I hope you rise to the occasion and fulfil your destiny," Vin, who plays the lead role of Dominic Torreto, wrote.
The Rock (aka Dwayne Johnson) joined the Fast & Furious franchise as Agent Hobbs in Fast Five in 2011 - but the 49-year-old didn't appear in the most recent film and has previously said he wouldn't appear in future films.
Vin Diesel wrote to his 76 million followers that he wanted to fulfil his promise of a perfect ending to "Pablo" - referring to his late co-star Paul Walker, who died in 2013.
"I swore that we would reach and manifest the best Fast in the finale that is 10! I say this out of love... but you must show up," the 54-year-old said.
Calling him "little brother Dwayne", he asked him not to leave "the franchise idle".
What's happened between them?
You might be wondering what went wrong between two people who have been part of one of the most successful franchises ever and even referred to one another as "family".
It's been described by their co-star Ludacris as "a delicate situation".
The pair have clashed with each other - with The Rock confirming they didn't shoot any scenes together for The Fate of the Furious.
One scene in the 2017 film starred both actors - but this was only due to clever editing.
The final week of filming for that film saw The Rock post a message on Instagram denouncing a co-star (who he didn't name at the time) for failing to "conduct themselves as stand-up men and true professionals".
It became apparent he was referring to Vin Diesel.
In an interview with Vanity Fair last month, The Rock said nearly "every single crew member found their way to me and either quietly thanked me or sent me a note."
And he said he regretted posting publicly - but meant everything he said.
It was reported a peace meeting took place afterwards, which The Rock says wasn't actually "a peaceful meeting".
"I would call it a meeting of clarity. He and I had a good chat in my trailer, and it was out of that chat that it really became just crystal clear that we are two separate ends of the spectrum."