The 26-year-old midfielder progressed through the youth ranks of La Masia with the hope of developing into the long-term replacement for Xavi.
Instead the Spaniard decided to leave Barcelona in 2013 to reunite with Pep Guardiola at Bayern after failing to establish himself as a regular starter.
Thiago was linked with a return to the La Liga giants in the summer with new manager Ernesto Valverde looking to add a creative midfielder to his ranks.
Marco Verratti emerged as Barcelona's priority target but Thiago was considered as the main alternative for the Paris Saint-Germain star.
Such a move appeared to be completely ruled out when in April Thiago decided to commit his long-term future to Bayern by signing a new deal at the Allianz Arena until 2021.
However, the Spaniard has now admitted that a move back to the Nou Camp can still "happen" with Barcelona still on the hunt for a playmaker to replace 33-year-old Andres Iniesta.
"I signed a new deal until 2021 with the intention of staying more years. I am very happy here right now. I'm only thinking about the season as it is very long and we don't have time to think about anything else. Then, at the end of the campaign, you think: 'this season I've been fine or not, I want a change' ... but right now I'm comfortable [at Bayern]," Thiago said to Catalunya Radio.
"Barcelona is Barcelona. At the end Barcelona will always be my home and not just because I love the club, but the city too. I will go to leave there once I hang my boots. I will always look there with affection not only for the club but because of the teammates. You never know [if I will return]. Maybe at the end of the season Bayern are not happy with me. Football changes a lot. In the near future [a return to Barcelona] can happen or it can happen in 2021 [after my contract expires]..."