The 27-year-old's season ended prematurely last term after he suffered serious ankle damage against Crystal Palace in March.
"Fletch came back a week early to make sure he started running with no reactions," explained Gustavo Poyet, his manager. "I saw him and everything looks fine. He's excited. People don't know sometimes that the players are like any of us.
"When you like so much to play football you're excited about the chance to go back."