Pompey defender Greg Halford is suspended, but Carl Dickinson returns after a ban and keeper Jamie Ashdown is expected to be fit after appendicitis.Midfielders Michael Brown and Richard Hughes may not feature because of an ongoing contractual situation. [LNB]Scunthorpe are still without defenders David Mirfin (foot), Niall Canavan (knee) and Michael Raynes (thigh). [LNB]But midfielder Michael Collins is available again after recovering from a shoulder injury. [LNB][LNB] MATCH PREVIEW Portsmouth, whose last three outings have all been away from home, return to Fratton Park in good form and within sight of the play-off positions. [LNB]Pompey have won their last two matches and are only five points behind the top six. They will be looking to pile more misery onto a Scunthorpe side which has struggled badly in recent weeks. [LNB]Since beating Humber rivals Hull, The Iron's form has disintegrated. They have lost their last five matches, scoring only four goals and conceding 14 in the process. Another defeat would make this their worst run since the 1997/98 season, when the club was in the bottom division. [LNB]But most of their problems have been at home. United, who are one off the bottom of the table, have been impressive away, with five of their six league wins and 15 of their 20 points coming on the road. [LNB][LNB] MATCH FACTS Head-to-head[LNB]• These clubs have met 12 times in the league. Portsmouth have won three of those matches, their most recent victory against Scunthorpe being a 6-1 thrashing in 1979. [LNB] Have your say on this match • Scunthorpe's last win against Pompey was a 4-3 victory in 1964. [LNB]Portsmouth[LNB]• A win for Portsmouth would give them 18 points from home matches this season - as many as they managed throughout the whole of last term. [LNB]• Pompey have kept only three clean sheets this season. [LNB]• They are averaging a Championship goal every 3.43 shots on target, which is the best return in the division. [LNB]Scunthorpe[LNB]• Scunthorpe's points tally of 20 after 20 matches is their lowest return for 11 years. [LNB]• They have lost all 11 league games this season in which they have conceded the opening goal. [LNB]• United have only picked up only 19 yellow cards this term.