The Blues are close to securing a move for the Crystal Palace star.
The winger has emerged as a Premier League star over recent years with a series of impressive performances for Crystal Palace.
He has often lacked consistency though, as star performances have often been followed by poor displays.
Everton are keen despite that, with Sky Sports reporting they have agreed a £30 million deal to take him to Goodison Park.
And Gray believes he could be a great signing for the Toffees so long as he brings a level of consistency to his game.
“If he is going to take himself to the next level, he has got to be 7/10 for five games and 9/10 in another game,” he told talkSPORT.
“If he brings some consistency to the undoubted individual talent he has and integrates it into team play, he could be a great signing.”
It remains to be seen whether Bolasie can find that consistency his game is lacking should he make the move to Everton.
At the price that the Blues are paying for him, they will certainly be demanding an improvement and a quick one at that.
With all due respect to Crystal Palace, he will be playing with a higher level of player at Goodison Park though and perhaps that will prove to be the difference next season and beyond.