The Lions sit second in the table, and travel to the team sat in fourth, with their hosts on Saturday having won four and lost two in the league so far this term.
Looking ahead to the game, director of rugby, Will Croker, said: " Going away to Petersfield is always a really tough ask.
"They usually have quite a good crowd and they're quite vocal. They're currently sat, I think, in their highest league position ever and they have a really, really talented side.
"It's probably better known for its forwards than its backs currently because they've got some really good players.
"Dan Sargent, Zac Conley, who's the most recent guy to have signed, he was captain of Chichester and he signed for Petersfield this year.
"Liam Perkins, who was Hampshire captain for years, a fantastic number eight, he was at Worthing when they were at level three.
"They've got some really talented players and we know the battle that's to come up front. We're expecting to be mauling a lot.
"We're expecting to have to get off the line and shot big fellas carrying the ball really hard and that's actually quite exciting.
"It poses a different threat to say an Old Tiffinians who wanted to throw the ball around and play fast and loose.
"This is a old fashioned roll your sleeves up and get stuck in."
Croker said they had trained well, splitting the week into work on defensive patterns before a switch to an attacking focus.
Bournemouth have brought some bulk back into their side, with Luca Firetto returning from illness after three weeks.
Croker said he, alongside fellow front rowers George Cotterell and Conrad Carkeet, can match up to Petersfield's physicality.
He feels they can do the same in the back row with Connor McCaffrey at six, Joe Rees at seven and James Kennedy at eight, with a good blend of physicality and carrying ability.
Matt Horne returns to the bench after a ban for a red card, while Bournemouth have been able to be consistent in selection in the backs.
Croker said: "It's an exciting week.
"We know that if we can get out there and put our game on them, we can stop their threats at source, then we can be a real factor in the game."