The Watford star was a shining light as the Hornets were relegated last season, impressing after a £25m move from Rennes.
He scored six goals and clocked up as many assists from 30 league matches last term and, as a result, has now forced his way into United’s thinking.
As well as Sarr, the report claims that Napoli’s Arkadiusz Milik, Bournemouth’s Josh King, Ivan Perisic of Inter Milan and Douglas Costa of Juventus are also on the club’s radar.
Milik is poised to leave Napoli for a new challenge elsewhere but United aren’t the only team keen, with Tottenham also admirers of the Poland international.
Solskjaer wanted King signed in January but ended up missing out, settling for a late loan move for Odion Ighalo instead.
Perisic was eyed by United during Jose Mourinho’s time in charge yet, when he ordered the signing of the Croatia international in 2017 and 2018, the club’s hierarchy said no.