Premier League club Chelsea have reportedly hired All Blacks mental skills expert Gilbert Enoka.

Enoka, known for the "no dickheads" policy he introduced to the All Blacks environment, has been brought on by Chelsea to help them develop a winning culture after the West London club went on a large spending spree in the recent transfer window, The Telegraph reports.

The appointment is short-term but will be demanding, the Telegraph's Matt Law and Charlie Morgan said in their report.

"Head coach Graham Potter's bloated squad is bursting with different personalities and egos, and there is an acknowledgement that Chelsea's expensive new signings could flop under the weight of expectation if the right culture is not created.

"That is the area Enoka has been hired to help with, and the 57-year-old will stress the importance of the team over the individual at a time when Potter has been left with the unenviable task of trying to help all of his new players settle in, while trying to make sure existing squad members do not become disillusioned.

"Successive managers and head coaches have questioned the mental fortitude of the Chelsea squad since the club last won the Premier League title in 2017."

Enoka has been with the All Blacks for over a decade, helping them to Rugby World Cup wins, an impressive Bledisloe Cup streak and domination of the No.1 position in the world rankings for 10 years.

He joined the All Blacks following their quarterfinal exit at the 2007 Rugby World Cup, quickly introducing his "no dickheads" policy to the side to make players and staff accountable to each other.

Enoka described a "dickhead" as "people putting themselves ahead of the team, people who think they're entitled to things or expect the rules to be different for them, people operating deceitfully in the dark, or being unnecessarily loud about their work".

"A dickhead makes everything about them. Often teams put up with it because a player has so much talent. We look for early warning signs and wean the big egos out pretty quickly. Our motto is, if you can't change the people, change the people."

His reputation has also seen him work with other big Kiwi sporting teams and names including the Black Caps, Silver Ferns and rally driver Hayden Paddon.