The Blackhawks initially said Campbell would miss seven or eight weeks.
Campbell says he still doesn't have a timetable to return. He won't play Friday when the Blackhawks open the playoffs at home against Nashville.
Ovechkin drove Campbell into the boards from behind, drew a game misconduct penalty for the hit and later got a two-game suspension. The injuries ended Campbell's streak of consecutive regular-season games at 388.
Campbell is in the second year of an eight-year, US$56.8-million contract.