Former Manchester City defender Micah Richards believes Mason Greenwood can become a superstar for Manchester United.

The young forward is showing his best form so far this season, scoring in wins over Leeds United and Wolves, along with the 1-1 draw against Southampton.

Some pundits expected Greenwood to play less with the arrival of Cristiano Ronaldo, but he was in the lineup for the 2-1 win over West Ham United on Sunday.

"He definitely has to start. We've seen him up front or in a wide position," Richards told Sky Sports.

"When he faces someone in a one-v-one you just think the ball's going to hit the back of the net.

"He's so comfortable and works hard. He's got absolutely everything.

"I don't want to big him up too much, but I believe he can be a superstar."