Tuchel claimed the England international has 'exceeded all expectations' since signing for the Bavarian club in January.
Dier has started ten of his 12 appearances in the Bundesliga for Bayern, where he has impressed - despite tough competition from Matthijs de Ligt, Kim Min-jae and Dayot Upamecano.
Tuchel highlighted how 'vocal' the former Spurs defender is as one of his strengths, amongst several other traits.