The centre-half's last start came in the victory at Stockport last month but he is now fully recovered from an ankle injury and could start at the expense of either Danny Livesey or Peter Murphy.
Keogh came through 65 minutes for the reserve team against Oldham on Wednesday night and impressed boss Greg Abbott.
Striker Gary Madine picked up an ankle injury against the Latics' second string but is expected to be included in the squad to face the Saints.
Striker Scott Dobie is pushing for a start against Alan Pardew's
side, as is former Derby midfielder Marc Bridge-Wilkinson as the Cumbrians look to turn around their home form having lost three of their first four home games in the league at Brunton Park.
Simon Lakeland is a long-term absentee with a medial ligament injury.