Nketiah, 21, has made 57 first-team appearances for the Gunners since graduating from the academy in 2017.
While the forward is yet to cement his place in Mikel Arteta’s first-team, he has thrived for England’s youth sides and became their record goalscorer at U21 level in October.
Despite this, Cascarino does not believe Nketiah is ‘ready’ for the Premier League.
He told The Times: ‘I don’t think Eddie Nketiah is ready for the Premier League, which makes Arsenal’s reliance on him surprising.’
Struggling Arsenal face Manchester City in the quarter-finals of the EFL Cup on Tuesday night and Cascarino added: ‘Only by playing on the counterattack, and showing conviction when they break, will they have a hope of winning.
‘Mikel Arteta’s team had only 29 per cent possession when they won 2-0 at Wembley in July and they’ll need to accept something similar for this Carabao Cup tie.
‘They should not press City and they are not good enough to out-pass them. I also can’t see them dominating at set-pieces.
‘But when Arsenal do have the chance to launch a counterattack, they must not break away half-heartedly.
‘In the defeat by Everton at the weekend the player in possession had few options or none at all so had to halt the attack until team-mates had advanced, and by then the chance had gone.
‘They have played scared football this season, whereas it was different when they beat City in the FA Cup: in that match players felt they had something to prove and they were buying into what the manager wanted.’
While Arsenal go into the Carabao Cup quarter-final sitting 15th in the Premier League, Manchester City are eighth having gone eight games without losing.