The Icelandic missed Tuesdays 1-1 draw with Tranmere through illness, as did Michael Tidser, with Arnason touch and go for the weekend clash at leaders Leyton Orient but Tidser is now fully recovered.
O'Connor and Frecklington are both available after sitting out one game bans and could return to the midfield at the expense of Mark Bradley and Rob Milsom.
Boss Steve Evans has no other injury worries, although Claude Davis has again suffered a set back with his groin injury and is set to be out for another month.
There is better news with winger David Worrall, who will return to full training next week after intense work with physio Dennis Circuit following a hernia operation.
No new additions to the squad are expected before the weekend.