They are two of four sides in danger of joining Stevenage and Shrewsbury Town in League Two next season, with both requiring results elsewhere to go their way.
Carlisle need to win against table-toppers Wolves as well as hoping Tranmere and Crewe Alexandra lose against Bradford City and Preston North End respectively - Graham Kavanagh's men also require a three-goal swing in goal difference to keep them up.
A draw could keep Tranmere up - providing Crewe are beaten and their goal difference is altered sufficiently.
With Crewe and Notts County still in danger of going down, Tranmere's caretaker manager John McMahon is refusing to give up hope of completing a final-day escape.
"We are aware what difficulties we face, where we need to improve and hopefully we can get a positive result on Saturday and address them," he told Sky Sports.
"I'm still full of confidence and belief that come Saturday at five o'clock that we'll retain our League One status."
Victories for Crewe and Notts County will guarantee their safety and the latter will be quietly confident ahead of their trip to Oldham Athletic, having taken nine points from their last five games.
Colchester United's goal difference makes them all but safe, having conceded fewer goals than anyone else in the bottom nine, and they could edge up another couple of places with a win at Walsall.
The identities of the four play-off participants are already confirmed although there is room for some movement between third and sixth place.
A win for Leyton Orient against MK Dons could see them jump to third while Rotherham United too can edge higher if they beat Swindon Town at the County Ground.
Peterborough United will finish sixth regardless of their result against Port Vale.
Wolves may have wrapped up the title already but they can make history with a win over Carlisle as three points would take them past Charlton Athletic's record third-tier points tally of 101.
Second-placed Brentford host a Stevenage side heading into League Two while Shrewsbury will hope to avoid finishing bottom of the pile when they travel to Gillingham.
Bristol City's Sam Baldock can help tie up his top goalscorer award against Crawley Town, who parted company with first-team coach Guy Whittingham prior to their goalless draw with Carlisle United in midweek, while Sheffield United end their campaign by hosting Coventry City.
