The Japan midfielder caught the eye in the draw at West Ham United.
"He's doing very well for us now," Ferguson said. "He has fantastic composure on the ball and his decision-making is good. He has a good selection of passes; he seems to always pick the more sensible pass.
"And he made a terrific first goal. There were a few involved in that build-up but he had the composure to take the player on in a tight area and roll the ball to Valencia for a tap-in. He's doing very well."