Kris Boyd criticizes Manchester United for transfer blunder involving 'exceptional' player

Napoli splurged approximately £25m to secure the signing of the Scottish international midfielder, and McTominay has made an impressive impact under the management of Antonio Conte.

McTominay, 27, has played three Serie A matches for Napoli so far and provided an assist in the 2-0 victory over Monza on Sunday.

That assist came just three days after he scored his first Napoli goal in a thumping 5-0 win against Palermo in the Coppa Italia.

Former Scotland international Boyd feels Erik ten Hag’s side have made a huge error in offloading McTominay, who played a total of 255 games for the club.

‘Scott McTominay went over there (Napoli), I watched some of the game on Sunday night, he was excellent,’ Boyd told .

‘He’s a real handful. The timing of his runs into the box… his game intelligence has improved so much.

‘I think a lot of people just looked at him as a big boy who can get around the pitch, but he is far better than that.

‘Dare I say it, Scott McTominay might be something that United are missing right now.

‘We saw it in terms of last season, coming off the bench and scoring. That enthusiasm, that know-how to get a game won, going and pressing and getting after teams… everyone watched United’s game (against Tottenham).

‘There is lack of urgency, passion and aggression in that United team and that is something McTominay has in abundance.’

McTominay, meanwhile, has revealed the main difference between playing for United and Napoli.

Speaking to Radio CRC, he said: ‘They are very different, in Serie A I would say there is much more tactics that you need to know, your role within the team and with your teammates.

‘Physically you make your presence felt, the Premier League is very different but also Serie A.

‘The tactical work is more intense in Italy. I was very impressed by the level of the Italian championship, from England I wasn’t always able to realise how I can do it now.

“I was impressed by the technical level of the teams but also of the players, starting with my teammates.’