Joe Launchbury admits there can be no late drop in standards as Eddie Jones prepares to finalise his World Cup squad.
England name the 31 players bound for Japan on Monday - almost a month before the official deadline - and play their only warm-up Test before the announcement 24 hours earlier when Wales visit Twickenham.
Launchbury is highly likely to feature among the travelling forwards but even the veteran Wasps lock and captain fears ruthless Jones having a late change of heart.
"There's been movement in the squad throughout the last six weeks and Monday will be the culmination of that," Launchbury said.
"It's been made pretty clear to us from day one when Eddie first arrived that everything we do in training and games is a selection process.
"Playing for England is a fantastic honour but you understand that if you don't train well or have a bad run of form, you'll probably find yourself out of the team.
"We all know we have to keep performing to keep our place in the team."