Manchester goalkeeper target Odysseas Vlachodimos is keen to leave Benfica after being criticised by coach Roger Schmidt.
The 29-year-old emerged as a candidate to join Erik ten Hag's squad ranks on Sunday, with Mail Sport revealing that the Red Devils had enquired with the Portuguese club about the Greece international.
United are keen to bolster their reserves between the sticks after bringing in new first-choice No 1 Andre Onana during this summer's transfer window for £50million.
Crystal Palace are the favourites to sign United's reserve goalkeeper Dean Henderson, but the England international has also received offers from Nottingham Forest.