The midfielder has opted to retain the same number with his new club that he wore during his distinguished seven-year spell at FC Bayern Munich, which concluded with Champions League glory last month.
Thiago takes the No.6 for the Reds shortly after it was vacated by Dejan Lovren, who wore it for six seasons before his permanent transfer to Zenit St. Petersburg.
Recent predecessors of the number at Liverpool include Luis Alberto, Fabio Aurelio, Markus Babbel and John Arne Riise.