For Swansea they have to better Oldham's result to make it into the play offs. It's not going to be easy. The Swans face Blackpool who themselves have a chance at automatic promotion.
Oldham face already relegated Chesterfield. The teams are level on points with Oldham having a +2 goal difference over Swansea and have scored 2 goals more. Therefore if Oldham win then Swansea would have to win by three more goals than Oldham's winning score.
For Wrexham there's the matter of league survival. A draw would be enough to keep them in the Football League and send Boston into the Conference.
Good luck to both teams.