National boss Stuart Lancaster is hopeful Courtney Lawes and Dylan Hartley will both play a part in England’s autumn international series.
Lawes was forced off with a knee injury after just 28 minutes of Saints’ 16-6 defeat to Saracens on Saturday, with Hartley suffering the same fate at half-time.
The duo linked up with England on Monday before being released on Wednesday as part of a co-ordinated programme between the national team and Saints.
The forwards won’t play any part in their club’s game at Leicester on Saturday and are to be reassessed by the England medical team at Pennyhill Park on Sunday.
The Red Rose start their autumn international campaign with a game against Fiji on Saturday, November 10 and conclude on Saturday, December 10, against New Zealand.
“They are in good hands at Northampton,” said Lancaster. “Courtney could be one to two weeks and Dylan a couple after that.”
There is some good news for Saints in that back row Phil Dowson is available to line-up against the Tigers at Welford Road after also being released.
Lee Dickson and Tom Wood are the only Saints players retained by England ahead of the Fiji clash.
Meanwhile, Leicester have received a double boost as scrum-half Ben Youngs and centre Anthony Allen have been given the go-ahead to play against Saints.
Lancaster added: “It has been a busy few days of training as well as injury assessment and in line with the EPS agreement coordinating the release of players, some will return for further treatment from their club and others to get some game time to put a marker down for selection for when we meet again on Sunday after the weekend’s games.
“We will not finalise selection for the Fiji game until after training next Tuesday and so for those going back and playing this is a real opportunity to stake a claim with a really big performance.”