Prop Joe Marler has made himself unavailable for England's summer tour of Australia, saying he needs to rest.
"Whenever you play for England, you have to be 100%," said Marler.
"Unfortunately I'm not in that place. I would be letting my team-mates and country down if I were to tour."
England will face Australia in three Tests - in Brisbane on 11 June, Melbourne a week later and Sydney on 25 June.
Marler will also miss England's one-off Test against Wales on 29 May.
He added the past season - in which England won a Grand Slam for the first time in 13 years and Harlequins reached the European Challenge Cup final - had been "very enjoyable, but sometimes difficult".
Coach Eddie Jones, who confirmed Marler would have been part of the squad, said he supported the decision and "admired his honesty".
"Joe played brilliantly during the Six Nations and he will be a big loss in Australia," added Jones. "He's a young man with a very bright future.
"There's no doubt in my mind he'll use this time wisely and come back feeling refreshed and ready to be part of England again."
Marler played in all five matches during England's Six Nations campaign, starting three and replacing Mako Vunipola in the matches against Scotland and Italy.
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