The visitors, who are currently sat in fifth position, will be aiming to end a four-game winless league run.
Match preview
Forest Green are currently in the relegation zone with two points separating them from safety, but they will have the chance to claim consecutive victories after beating Exeter City in the Football League Trophy in midweek.
Two own goals and strikes from Jamille Matt and Corey O'Keeffe helped Forest Green claim a comfortable 4-1 victory, ensuring they have only lost one of their last four matches in all competitions.
The midweek win was a much-needed boost after Ian Burchnall's side gave up a two-goal lead last weekend to draw 2-2 away to Port Vale.
While they are winless in their previous three away games, Forest Green have won their last two home matches in all competitions.
However, Forest Green's performances have been inconsistent at The New Lawn this season, with four of their seven home league games ending in defeat.
Meanwhile, Portsmouth are sat in the playoff places, and they head into the weekend eight points adrift of automatic promotion with two games in hand.
Although Danny Cowley's side will be looking to close that gap, they will be wary of falling out of the top six after failing to win their last four league games.
Their previous two home matches in League One have finished all square, while they have also lost their two away games, including Monday's trip to the Valley.
Charlton Athletic took a two-goal lead into half time thanks to goals from Ryan Inniss and Corey Blackett-Taylor, before a Marlon Pack red card and an Eoghan O'Connell strike wrapped up a 3-0 victory for the hosts.
Having conceded three goals in their previous two away trips, Pompey will be looking for an improved defensive performance on Saturday.
Forest Green Rovers League One form:
L
L
L
W
L
D
Forest Green Rovers form (all competitions):
L
L
W
L
D
W
Portsmouth League One form:
W
W
D
L
D
L
Portsmouth form (all competitions):
W
D
L
W
D
L
Team News
Burchnall made a number of changes to his side for the midweek win over Exeter, and the Forest Green boss is expected to name a side similar to the one that started against Port Vale last weekend.
Jordan Moore-Taylor will feature in a back three alongside Baily Cargill and Christian Marques, with the trio hoping to keep a clean sheet for the second straight home league game.
Connor Wickham will look to add to the five goals he has scored this season, and the 29-year-old could be joined in a front two by Armani Little.
As for Portsmouth, they are still expected to be without the services of Louis Thompson, Jayden Reid and Joe Rafferty due to injury issues.
Pack will serve a one-match suspension, and the midfielder is likely to be replaced in the starting lineup by Jay Mingi.
After coming off the bench at half time against Charlton, Michael Jacobs may be presented with a starting place for Saturday's contest.
Forest Green Rovers possible starting lineup:
McGee; Moore-Taylor, Cargill, Marques; O'Keeffe, Hendry, Stevenson, Boyes; Peart-Harris; Little, Wickham
Portsmouth possible starting lineup:
Griffiths; Ogilvie, Raggett, Morrison, Robertson; Dale, Morrell, Mingi, Jacobs; Bishop, Scarlett