Mellor told liverpoolfc.tv: "From what I have seen of Buchtmann he seems very composed with good energy and a great engine which all modern day footballers need to have.
"He can play left-back or in midfield - which is similar to the role Stephen Warnock plays.
"He also played well in the recent games in the UEFA U17s European Championships for Germany and that is bound to give more confidence. Liverpool's FA Youth Cup run will also give him added belief from playing in big stadiums in front of big crowds.
"Moving to Melwood to train with the reserves is a big step and it is important that he works hard in training and keeps getting noticed by the coaches. It is also important that he is outgoing and not too shy as you have to fit in with the lads already there."