Pierre is set to miss the majority of the rest of the season after an operation on Monday.
The 24-year-old picked up the injury against Blackburn Rovers in their 1-1 draw on December 23, in which he scored his first goal for the club.
Northampton’s manager Jimmy Floyd Hasslebaink said: “It’s a huge blow because he was playing ever so well. He was grasping what we wanted and we are going to miss his physicality.”
The boss has said his defender has the same injury as Aaron Phillips but expects his team to cope with the loss of Pierre, with other members of the squad expected to fill in.
He said: “You have to be flexible in this business and we have to adjust.”
Burton midfielder Martin Samuelsen will use the international break to recover from illness after pulling out of Norway U21's games.
Jonas Lossl is staying 'optimistic' over Huddersfield's chances of survival this season and has urged his team-mates to 'go for it'.