Vidic is recovering from serious knee injury suffered last year.
"Vida won't be ready for going on the tour but hopefully he'll be ready for the start of the season," Ferguson told manutd.com.
"We sent him to a complex in Spain last week and he enjoyed it. It gave him a break mentally as it is not easy.
"He's been the only one in the gymnasium in the last couple of months or so because we've been reasonably injury-free.
"He's not running, he's just been in the gym."