Iwobi has played a part in 27 Premier League games for Everton so far this season but has only scored once while creating further two goals.
The Nigerian is mostly deployed in the right-wing and started against Tottenham Hotspur on Friday in their 2-2 top flight draw at Goodison Park, but struggled to make any direct impact in the game.
Ex-Everton star Ball is of the view that Iwobi has not been good for the Toffees so far this season, with him lacking consistency up front while contributing very little in terms of real attacking threat.
Ball explained that Iwobi still struggling to nail down a starting role under Ancelotti despite vacant spots opening up owing to their injury woes suggests he is yet to earn the trust of his boss at Goodison Park.
“Iwobi is on the bench one week, comes on and does well for 20 minutes, but then struggles to find consistency”, Ball wrote in his Liverpool Echo column.
“That isn’t good enough.
“He’s here to create opportunities and score goals. How often has he done that? It’s as simple as that.
“It’s nothing against him or his attitude but he needs to be doing his main job: scoring goals and making chances.
“We have had a lot of injuries over the season and he still hasn’t been able to force himself into the starting XI.
“That shows Carlo Ancelotti cannot trust him or doesn’t know what you are going to get out of him.
“He is skilful at times, but he doesn’t always take his chance.
“Go and get at your full-back and beat him, but Iwobi doesn’t seem to have that confidence in his own ability to go one-vs-one with a defender and ask a question.”
Everton will resume their chase for a European spot finish in the league when they travel to Super League side Arsenal on Friday and it remains to be seen whether Iwobi will play a part in that clash.