The Spain international was full of praise for his club team-mate and agreed with the notion that he is the greatest player of all time
The diminutive attacker has earned worldwide praise after becoming Barca's all-time leading scorer in official competitions following his hat-trick in Tuesday's 5-3 victory against Granada.
Gerard Pique said earlier on Wednesday that Messi was the greatest player ever, and Thiago has now agreed with the defender's assertion.
"For me, he is the best," he said during a press conference. "We are in an era which is marked by just one player.
"I will be able to say that I played with Messi. I have never seen anyone play like him.
"The things he does at the age of 24 are remarkable and he still has a long way to go.
"He will have to succeed with the Argentina national team, but it is crucial that people in his country give him more trust."
Barca coach Pep Guardiola is pessimistic about the Blaugrana's chances of retaining their Liga title, but Thiago has refused to concede defeat just yet.
"We will work to stay in the race and win all the matches we can, but it does not depend on ourselves," he noted.
"We have to keep our hopes up."