The Brazilian, who departed for Fiorentina last week, averaged a two out of 10 for his four league appearances this season.
That was easily the lowest mark in the United squad, although few first-team stars have covered themselves in glory so far this campaign.
The da Silva twins have been woeful, Rafael and Fabio both with four out of 10 marks, while Chris Smalling, Ashley Young and Antonio Valencia all share the same score.
Nani and Wilfried Zaha have scored just three out of 10 although the latter has played only 36 minutes of football for United.
And what about some of the bright spots? Well Wayne Rooney has averaged a nine out of 10 mark for the season so far, while teenage sensation Adnan Januzaj has dazzled his way to an eight out of 10.
It's not without reason that just six out of the 25-man squad have averaged at least seven out of 10 this season.
United have endured a poor first season under Moyes, and they currently sit seventh in the Premier League table with 22 games played.
They've already lost more league games than they did last year, and are six points off fourth spot in the race for Champions League qualification.
To see the full list of Manchester United player ratings from the Guardian, click this link.