"This is definitely the strongest squad I have been involved in," Rooney told Inside United. "I think that has been proved by the way in which players have come in and performed when someone has been out with an injury.
"We have dealt with setbacks like that very well. That is when you see the strength of the squad.
"I think being champions has given us a lot of confidence. The pressure to succeed is still there especially as every team we play always wants to do well against us. But there is a real belief in the dressing room."
The summer arrivals of Nani, Anderson and Owen Hargreaves has had a major impact on Ferguson's squad, although of all the new arrivals, it is Carlos Tevez who has dazzled the most.
Many pundits predicted Tevez and Rooney were too alike to form an effective partnership but those views have long since been dismissed.
Nineteen goals between them so far this season may be only the same figure as Cristiano Ronaldo has managed on his own but considering Rooney has suffered a broken foot and an ankle injury already this term, the figure is hugely impressive.
"I definitely believed our partnership would work out," he said. "Carlos is a great player. He has done really well since he joined the club and I think we are working well together.
"Our partnership proves that all good players can play together no matter how similar you are."