Mount's troubled PS60million switch from Chelsea was one of the Dutchman's costly missteps in the transfer market for which he ultimately paid the price.
The 25-year-old midfielder has faced a torrid time since joining Old Trafford in 2023, with injuries hampering his development and limiting the opportunities for Ten Hag to mould him.
However, the pair's relationship has come to an end after United chief executive Omar Berrada and sporting director Dan Ashworth informed Ten Hag of his dismissal after Sunday's 2-1 defeat at West Ham United.
Ten Hag's tenure at United came to an abrupt end following a string of poor results, including four defeats in the first nine league matches of the season after a disappointing eighth-place finish the previous campaign.
Mount, who managed only one goal and one assist in 25 appearances under Ten Hag, is now seen as one of the less successful acquisitions alongside the PS82 million signing Antony.
However, following the announcement of Ten Hag's departure, Mount took to Instagram to bid farewell to his ex-boss, writing: "Thank you gaffer. Wish you all the best for the future."
The former Chelsea ace, currently sidelined by his latest injury, was not alone in his sentiments; several teammates also reached out on social media to thank the Dutchman.
Bruno Fernandes, the club captain, shared: "Thanks for everything boss! I appreciate the trust and the moments we share together, I wish you all the best in the future.
"Even knowing the last period hasn't been great from all of us I hope you fans can keep with you the good things the manager has done for our club!"
Alejandro Garnacho also expressed his gratitude: "Thank you for everything, boss. I will always be grateful to you for giving me the opportunity and the confidence to play for this club.
"It hasn't gone as well as we wanted, but I will remember the good times we had together, and I wish you all the best in the future. Thank you very much Erik."
Meanwhile, Kobbie Mainoo echoed the sentiments of appreciation and optimism, saying: "Thank you for your trust and belief in me and for giving me the opportunity to play for my boyhood club. I wish you all the best for the future."