Gloucester wing Sharples wasn't included in England's 24-man travelling squad for Sunday's clash in Paris but has been called up as a like for like replacement after Strettle failed a late fitness test.
Saracens star Strettle has been suffering with a sternum problem since the win over Italy in Rome.
He was fit enough to start the Twickenham encounter with Wales a fortnight ago but the injury has flared up in training.
"Charlie has trained with us throughout the tournament so he has spent a lot of time with the other guys," said interim head coach Stuart Lancaster.
"He almost made the World Cup squad and this is a great opportunity for him.
"It's unfortunate for David but he has been fitness-tested by the medics this morning and is not 100 per cent so it is a straight swap and Charlie is ready to go."
Strettle's setback hands Sharples a huge opportunity to impress having been on the fringes of Test selection since last season.
The 22-year-old narrowly missed out on a place at the global gathering in New Zealand last autumn and had been tipped to replace 2005 Lion Mark Cueto in a new-look England side for the 6 Nations.
Sharples scored 18 tries in the 2010/11 season but Lancaster turned to Strettle instead, with the Gloucester youngster missing out on the matchday squads against Scotland, Italy and Wales as England opted for more versatility among their replacements.