Gloucester fly-half Danny Cipriani will undergo extra fitness work away from England's second World Cup training camp.
Cipriani will do specialised strength and conditioning work off site, along with flanker Sam Underhill and fullback Anthony Watson.
Head coach Eddie Jones has called up 40 players for the training camp in Bristol, including Mike Brown, Alec Dombrandt, Marcus Smith, Tom Dunn and Ollie Chorley despite their missing out on last month's training squad.
"Some players we feel will benefit now from being away from the camp for a little bit and will do specialised strength and conditioning work," Jones said in a statement. "Our preparation is about making sure the players peak for the World Cup.
"We want to keep the squad fresh and alive which is important and we want to make sure there is a little bit of cooperative competition for selection and edge around.
"The ante goes up again in this week. The players who have come in from the Premiership final will increase their contribution and the other guys are in their fourth week and are starting to get near good physical condition."
The deadline for Jones to select his final 31-man squad for the tournament is Sept 2.
England's next games will be against Wales and Ireland at Twickenham in August, and Italy in Newcastle on Sept 6, as part of the Quilter Internationals ahead of the start of the Rugby World Cup in Japan against Tonga on Sept 22.