The England international spent last season on loan at Bournemouth, making 27 appearances in all competitions but has found playing time very hard to come by since returning to the Emirates Stadium.
Wilshere has been afforded 25 minutes of English Premier League action which threatens his involvement in the Three Lions' plan ahead of the quadrennial showpiece after Gareth Southgate overlooked him for the friendlies against Germany and Brazil.
"For him to get more games and to be ready for the World Cup, he has to play more so if he's still there and he's not getting the opportunities to play, I'd advise him to leave," Ighalo told Premier League Daily.
“He's a very good player, he can't be there sitting on the bench. If he cannot play at Arsenal, he can play at any other big team in the Premier League."
Ighalo also revealed he was reluctant to leave Vicarage Road but ‘had to do what was best for him’.
“Words cannot express it because I had a really great time at Watford," he continued
"The fans are still close to my heart. Everything around the club is just great.
"It was a pity I had to leave but I had to do what was best for me,” he concluded.