The Argentine winger has yet to impress since arriving at Stamford Bridge from Manchester United last summer.
Interim head coach Calum McFarlane put his faith in the Argentine in Sunday's win over Leeds United, but reports suggest this only came due to the absence of Cole Palmer.
The 21-year-old has divided fans and now Wright-Phillips has spoken to Sky Bet about how Garnacho may need a change in attitude to succeed in the with Chelsea or suffer being sold in the summer.
"I feel like he may need to put his ego a little bit in check. Because in a Premier League, a half season or one season is not good enough. To be at a level where people want to buy you, it has to be a consistent thing.
"It’s okay scoring sometimes, but I know the Chelsea fans, the least they need from you is 110%. If they see you working that hard for that badge, they will back you.
“I don’t know whether that’s tactically, or whether he’s not happy, but they got nearly six or seven wingers, so he’s gonna have to do something because (Jamie) Gittens might just switch on at any given point."
South American giants River Plate said to be keen on snapping up Garnacho, who is unlikely to feature against Nottingham Forest on Monday afternoon now that Palmer has returned.
However, with a new manager to step in during the summer, Garnacho could be handed more chances to prove his worth after a poor start with the Blues.