South Africa's former skipper believes that Cook faces a difficult challenge to lead the team to success following the 5-0 Ashes defeat to Australia in the winter, but believes that his performances with the bat could be key.
"He needs to answer some important questions [such as] do the players trust him?" Smith told reporters.
"It's going to take a lot of energy. Captaining and opening is taxing. He is going to have to focus on performing.
"England to me look a little stale. They look like they need new energy, they look like they need a direction, someone to galvanise them."
Smith captained South Africa for over 10 years before retiring in February.