United had been heavily linked with the Spain Under-21 star, who seemed certain to join the Red Devils after deciding he needed to leave the Nou Camp in order to further his World Cup ambitions.
Instead, Thiago's former boss Pep Guardiola has stepped in, with the player now looking certain to join Bayern Munich.
Despite the disappointment, Moyes remains resolute in his squad-building strategy.
"I never said at any time he was," said Moyes, when asked if the Spain Under-21 star remained a target.
"There are people we are actively chasing and we are happy with the way things are going."
It does appear Benfica defender Ezequiel Garay has agreed to join United though, with reports claiming a transfer is imminent, although there has been no official word from either club.