The German defender has recently spoken about his improved form and hopes of staying at the club beyond the end of the season.
And Dixon is not impressed with Mustafi piping up.
He told The Handbrake Off podcast: "He [Mustafi] seriously needs to have a word with himself and pipe down a little bit."
He went on to say: "Bang me 25 appearances out and 15 clean sheets then he can do what he likes with his hair and his sunglasses.
"Just sit back down for a bit and carry on churning the results out."