I'd imagine it has to be at least 3 games for violent conduct?
For violent conduct yes, minimum three game ban.
Mings is thought to be facing more for the head stamp though.
From the linked article:
"If Ibrahimovic is found guilty he faces a three-match ban, ruling him out of United’s FA Cup quarter-final tie with Chelsea next Monday, as well as the Premier League matches against Middlesbrough and West Bromwich Albion".