Pierre has not played since being substituted during the first half of the Cobblers’ 1-1 League One draw with Blackburn on December 23 and has now had an operation to address the problem.
The club posted on Twitter on Tuesday morning: “After speaking to the media this morning, Jimmy Floyd Hasselbaink has confirmed that Aaron Pierre will be out until mid-April after undergoing surgery on the groin injury picked up against Blackburn Rovers.”
Pierre had made 23 appearance in all competitions this season when misfortune struck.
Nemanja Matic believes Manchester United boss Jose Mourinho's driven methods and high expectations will bring the club more success.
Cardiff remain unhappy with Derby's decision to postpone Sunday's Sky Bet Championship game at Pride Park.