The 24-year-old is currently second-choice at German club Freiburg behind France goalkeeper Simon Pouplin but is still highly regarded. He is 6ft 5in and was formerly at Stuttgart.
United are weighing up their options because Tomasz Kuszczak is keen to move on and there are concerns over Ben Foster's form.
United have scouted several keepers but anticipate Edwin van der Sar may yet sign another one year deal.
Big shoes to fill: Van der Sar
Foster's prospects hit by rumours of renewed United bid for Schalke's NeuerUnited linked with Adler move after German keeper is spotted at AnfieldMANCHESTER UNITED FC