According to Mark Ogden from ESPN, prior to his retirement, Sir Alex Ferguson had set up a deal for the Spain midfielder to join from Barcelona.
Thiago was 22 at the time and although he had just captained his country to the European Under 21 Championships, he hadn't yet established himself as a regular at Barcelona.
A £17 million transfer was on the cards but David Moyes vetoed the move upon his arrival in June - apparently telling United he "did not know enough about the player's credentials".
As an absolute last resort and with it looking like no new additions would be coming in, Moyes went and drafted Belgian midfielder Fellaini in from his former club Everton as his only signing in the window.
He spent five years at United before being offloaded to Chinese outfit Shandong Luneng for £10.5 million in February 2019.
Thiago, meanwhile, would then reunite with former manager Pep Guardiola in Germany for a relatively small fee of €20 million and has established himself as one of the world's top midfielders.
Running things in the middle of the park, Thiago has won seven consecutive Bundesliga titles and was irresistible as the Bavarian outfit won the Champions League under Hans-Dieter Flick in the extended 2019/20 campaign.
United have once again been linked with him in recent times, while Liverpool did appear frontrunners for his signature not too long ago.
But Thiago, who dropped a masterclass in the game against Germany, broke his silence on the situation by simply playing everything down.
"I have not told anyone that I'm leaving," he said in a press conference ahead of Spain's game against Ukraine, as per The Mirror.
"Every year you put me at a different club.
"For me, my future is tomorrow's game and there is nothing more to say. I neither care nor am I interested. What interests me is tomorrow."
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