Memphis arrived from PSV as a £19m purchase in the summer as the next big thing but his attitude and mentality is letting him down.
Driving around in his £300,000 BMW with personalised plates, the lad may have been top scorer in Holland last season and voted the best young player at the 2014 World Cup, but he's got a lot of work to do at United.
Bar one or two moments of fleeting brilliance, the 21-year-old Dutchman has proved to be disappointing, and his lackadaisical and lazy attitude has seen his relationship with United fans hit a new low.
It's unfair of course to single out an individual for the concession of a goal as a team but it was impossible to ignore the contribution Memphis made in the late Costa goal at Stamford Bridge.
Louis van Gaal has used Depay as an impact sub for much of the season but on Sunday the only impact he had was to cost us two points.
The Dutch winger came on to field for Jesse Lingard in the 87th minute and promptly did what's he done so often this season and cheaply gift the ball back to the opponents.
Rather than attempting a simple ball to Morgan Schneiderlin- or run the ball to the corner- Depay made a lame attempt at a pass which merely rolled into the arms of Thibaut Courtois.
To contrive this, his failure to work hard, track back and make amends for his error- instead merely strolling back into his own half- directly resulted in the Chelsea goal.
He's clearly a fantastic player- to be signed for £19m at 21 years of age by a club of United's stature you've clearly got talent- but he has to back that up by improving his work rate and attitude to win back his place in the side.
As we saw first hand with Angel Di Maria last season, talent alone isn't enough to be a success at United- or, I suppose, any other top club.
Memphis is in danger of going the same way as the Argentine if he continues with his current level of performance.
You can cut Memphis some slack to an extent: a young player in a new league with a huge price tag at the biggest club in the world, and I still think he will come good- but, to do so, he needs to get his head down and iron out the flaws in his game.