The Spanish Under-21 international has been linked with the Red Devils throughout the summer and a deal is now near to being struck between the two sides.
United and the Catalan club have agreed a fee in the region of £17.5m and the Red Devils have also agreed a five-year deal with the player, as discussions are well advanced and "only little details remain to close the operation", reports The Sun.
A source told further added: "Thiago is very excited about the chance to play in the Premier League. He's always loved it."
Thiago captained the Spanish Under-21 side to victory at the European Championship this summer, as he notched a hat-trick in the final.