The reason for Joe Marler's England omission revealed

The 31-year-old has recently opened up about some mental health problems that he needs to take care of over the summer.

Sources suggest Marler, who also missed the tour of Australia in 2016, needs a break to be in the 'correct head space' in the run-up to the 2023 Rugby World Cup.

The England and Harlequins prop publically opened up about his battles with mental health last year when creating his documentary 'Big Boys Don't Cry'.

The documentary followed Marler as he travels around the UK to open up the conversation around mental health challenges and to learn about how people manage with their mental wellbeing.

From taking the plunge in cold water swimming and getting involved in singing in a choir, the prop dived into the subject head first literally.

He also discussed his mental health with former England teammate James Haskell.

Marler on Leonard: "My Idol - I still pinch myself when I'm in his company. A juggernaut on the pitch and a legendary drinker and socialiser off it."

Marler on Farrell: "The only indispensable player is Farrell. He is to England what Cristiano Ronaldo is to Portugal, or what Steph Curry is to the Golden State Warriors. With his leadership, ability and drive, England are a different animal. Owen takes things by the scruff of the neck, just like his dad."