On the High Performance Podcast, host Jake Humphrey read out the fan's message during his interview with Staveley.
The message read: "We are grateful for the investment, for the progress on the pitch and finally being able to see our club compete again. But a football club is more than just a business.
"It is a community, it is a family. And families thrive on communication, warmth and understanding.
"Without Mandy leading the charge in that regard Newcastle United risks losing a vital connection with its soul - the loyal, passionate black-and-white army.
"For the club to rediscover its voice, to reconnect with its fans and to bring back some of that much-needed warmth that Amanda Staveley so brilliantly provided."
In response, an emotional Staveley began: "That's really hard. God, sorry."
Staveley then continued: "That is really hard because that is really lovely and that is why I went into Newcastle because the fans are just so incredible and they really are.
"Leaving was the hardest thing I have ever done and took a long time to understand and do what is right for the club and PIF is going to be an incredible partner for Newcastle, and the Reubens.
"We left it in very safe hands. There are so many great people with great hearts who put so much into that club and into the community and in to everything about it.
"So for me it was a privilege. Every day I would go to work and think, 'God, I am so lucky to do this job'."