In the summer transfer window, McTominay sealed a lucrative transfer move to Serie A, as he completed a £25.7 million switch to Napoli.
The Scotland international, who came through United’s academy, has made an immediate impression under Antonio Conte with two goals and an assist in his last three appearances.
And Zola admits he did not expect United to let McTominay leave Old Trafford in the summer.
‘I’m very surprised,’ Zola said on Wednesday.
‘I could not believe that Manchester United released him, to be honest.
‘I don’t really know what’s the reason but obviously for Napoli it’s been a great deal.
‘I think everybody loves him so far, he’s scored goals, performed very well, he left me a little bit dazzled, to be honest, I didn’t expect that.
‘Obviously it’s a big thing for Italian football, he’s doing very well.’
Last week, Paolo Di Canio also criticised United’s call to offload McTominay, given his impressive start to life at Napoli.
‘I would go to those at Manchester United to arrest all the directors – how can you give away McTominay?’ Di Canio said in an interview with Il Mattino.
Napoli currently sit top of Serie A with 16 points from their opening seven matches.
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