First-leg deficits are notoriously difficult to reverse to Charlton will need to be on their mettle.
Swindon could have been out of sight if they had not been so profligate in front of goal on Friday. As it is, the Addicks trail by a solitary goal. They must avoid going behind at The Valley or the task could then be beyond them.
Goals have been a problem for a while now and Charlton may need extra-time if they are to progress to Wembley.
Sam Sodje was not 100% fit on Friday and may find it difficult to play two games in three days. Miguel Llera is likely to step in.
Kyel Reid will have a part to play and Parky will have to decide whether to satrt with him or bring him on later. Bailey would switch to the middle at the expense of Racon if Reid gets the nod to start.
Forster is another who could return with Mooney making way.
Nicky Forster, his eye for goal will be vital to Charlton’s chances.
Billy Paynter’s hamstring problem is likely to sideline him again. Bolton loanee,Danny Ward, will again partner Charlie austin up-front.
Greer will need to snuff out the menace of Forster.
Neil Swarbrick from Lancashire, who was in charge when Charlton lost 4-0 at the New Den in March, will be the referee.