Kasey Keller is set to keep his place in goal for Fulham after keeping a clean sheet against Chelsea last weekend.
The American will get the nod over Antti Niemi and Tony Warner and will bid to stop a Portsmouth team that scored seven goals against Reading.
Lawrie Sanchez is expected to select the same side that drew with The Blues, meaning Keller gets a further chance to impress.
The 37-year-old was making only his second Premier League appearance for Fulham and received high praise for his performance at Chelsea.
“Kasey kept a clean sheet, which was only the second one we’ve managed this season,” Sanchez said.
“I made a decision against Chelsea to go with Kasey, and he didn’t let in any goals, which is all you can ask a goalkeeper to do.
“Antti Niemi is being plagued by the wrist that he injured in pre-season, and it still isn’t 100 per cent right, but the good thing about having three goalkeepers is that it gives us good competition.
“Some players might not like that, but the facts of life are that you need competition if you are a Premier League club.
“Antti was fantastic for us last year, and I have said before that we would have been relegated without the saves he made late in the season.
“But that was last season. With one thing and another, he wasn’t fit for pre-season, and then he was injured in the warm-up at Arsenal.
“Unfortunately, you can’t wait for ever for players to be right. You have to look at alternatives, and if you play well, you deserve a chance.
“Kasey has the shirt, Kasey played on Saturday, and he kept a clean sheet, so it is more than likely that he will play against Portsmouth.
“But that is what football is about. If you play well, you usually stay in the team.”