The 32-year-old was on Leeds United's books until 2012.
The ex-Leeds United man would sell the midfielder.
Leeds United announced the Dane as their new head coach on Thursday.
The former Leeds United midfielder has been impressed with another member of Garry Monk's side.
Vieira made his Leeds United debut under Steve Evans less than a year ago.
Leeds United lost against Brentford in the Championship on Tuesday.
Leeds United failed to win against Queens Park Rangers in the Championship this season.
Leeds United failed to win against Ipswich Town in the Championship on Saturday.
Leeds United lost against Huddersfield Town in the Championship on Sunday afternoon.
Pontus Jansson joined Leeds United on loan from Torino in the summer of 2016.