The wide receiver underwent surgery yesterday, following a tackle by the rookie safety which left him with an anterior cruciate ligament tear.
The 25-year-old tweeted: "Don't blame [Vaccaro] It was a routine tackle. I admire how feisty a player he is too. He's going be great for us.
"Appreciate all the concern and love. Staying positive through it all. Time to get stronger physically as well as mentally. Surgery was successful. Road to recovery starts now."
Morgan recorded 379 receiving yards and scored three touchdowns for the Saints last season.