The Mexican striker, who suffered concussion last month in a pre-season friendly, will miss the first few weeks of the new season as a precaution.
"Chicharito won't be involved for maybe another two or three weeks - considering he had a concussion some years ago we are just playing safe with that but he should be back by the end of August,” Ferguson told reporters.
The Premier League champions face North West rivals Manchester City in the Community Shield on Sunday.
Despite silverware up for grabs, the Red Devils boss has revealed that his team will treat the match as preparation for the new League campaign.
"I have always viewed the Community Shield as a stepping stone to the first game of the season,” he added.
"It's very easy to get emotional about this type of game but I don't think we will be changing our policy. There may be two or three players who need the game on Sunday."