Anderson admits he's failed to live up to standards expected at Manchester United.
Anderson has failed to deliver a goal threat from midfield with just one strike in 96 appearances - in United's 3-1 victory at Spurs earlier this season.
He admitted to The Sun: "I'd be lying if I said I wasn't disappointed in my goal performance at United. In fact it makes me sad.
"And one of my first objectives is to get back to the condition I was in at Porto, then start scoring goals which decide matches because that's vital for any player's career.
"I know that a footballer of my ability, who is accustomed to playing an attacking role and is used to scoring goals regularly, must be sad to only score a goal every six months.
"But I must not let myself feel dispirited. I need a run of games where I'm doing well."