Unlike his predecessor Sir Alex Ferguson, the 50-year-old does not select his team until close to kickoff.
"This manager's a bit different in that he doesn't name the team beforehand," Ferdinand told BT Sport. "You don't really get to know the team. The old manager used to give you a little bit of an idea if you'd be playing and stuff.
"When you know you're playing, the intensity goes up a little bit more on match day. That's what you need to try to make sure you're doing, even if you don't know you'll be playing – to try to get to that intensity you'd be at when you know you're playing.
"It's hard. It's hard to do that mentally because you spend a lot of nervous energy thinking: 'Am I playing' or 'Am I not playing?' and you're just going round in circles in your head and turning into a madman."
Ferdinand will be part of the BBC team that will cover the 2014 World Cup finals in Brazil next summer.