Kenny Jackett will have to make changes to his defence when Pompey visit Accrington on Saturday.
Brandon Haunstrup limped off towards the end of last week’s draw with Peterborough and is set for a spell on the sidelines.
Christian Burgess also misses out on the trip to the Crown Ground, serving a one-match ban after collecting five yellow cards.
The Blues boss said: “Brandon is having an operation on his meniscus on Friday. It’s a straightforward one and we estimate him being out for six-eight weeks.
"Brandon is having an operation on his meniscus on Friday."
“He’s had a good total of games so far this season and certainly would have been looking to build on it.
“He hasn’t disappointed anybody when he’s been in the team and so it’s a frustrating one. He’ll be missed.
“We haven’t got any other new injuries, although Christian is suspended. Andy Cannon and Sean Raggett have both trained without any problems and are available.”