Saints duo Alex Waller and Ben Foden have been added to the England squad as cover.
But Luther Burrell has not headed to Pennyhill Park for training as the centre continues to be assessed by his club after picking up a hand problem in Saturday’s win over Ospreys.
Tom Wood will take his place in the 41-man group that has assembled in Surrey as soon as his wife has given birth to the couple’s third child.
The presence of Wood and Burrell would take the Saints contingent to nine, with Dylan Hartley, Courtney Lawes, Calum Clark, Lee Dickson and Stephen Myler also involved.
For Waller and Foden the call is a welcome one after they were surprisingly left out of the EPS squad, which was named last Wednesday.
Waller provides back-up for Harlequins prop Joe Marler, while Foden helps cover for the players who were in European action on Sunday.
But for Burrell there is an anxious wait as he bids to be fit in time for next month’s four-Test series, which begins with a game against New Zealand at Twickenham on November 8.
“We always anticipated bringing in additional players following the European games, either to cover injuries or for training,” said England head coach Stuart Lancaster.
“Luther will be assessed by a specialist over the next 48 hours and our medics are in close contact with Saints so we’ll know more in a few days but it’s great to be able to bring in Henry (Slade).
“Injuries are inevitable but we are excited about the group we have in camp. We are raring to go and looking forward to getting out on the training pitch on Monday.”