Curry had only just returned from an injury to the hamstring on his right leg sustained on club duty for Sale against Harlequins on January 8.
The 24-year-old flanker had been due to make his comeback for England against Wales on Saturday only to damage the same muscle on his left leg in training.
“It’s a grade 2c hamstring injury on the opposite side to the one that he did six weeks ago. It’s a soft muscle injury that extends into the tendon. It’s four to six weeks,” Sale boss Alex Sanderson said.
Curry missed the first two rounds of the Six Nations and having impressed over 80 minutes at Franklin’s Gardens on Saturday, he encountered a setback on his first full day of training with Steve Borthwick’s men.
“Tom played 80 minutes for us on Saturday. I’m not entirely sure of what he did with England on Monday,” Sanderson said.
“It was something to do with the loading and the physical demands of an international camp compared to your club.
“He’s frustrated. How good was he against Northampton? Tom knows his body and his mind better. This is not a guy who needs two or three games to warm up, he can just go straight in and be at the top of his game.”