Peterborough due to the absence of Elvis Hammond.The Robins striker has picked up an ankle injury and will miss the clash at London Road, which could see the club take another giant stride towards inevitable relegation.
Cheltenham's status as a League Two club could be confirmed after Easter Monday's home clash against Yeovil, but Allen will be looking for plenty of spirit from his side regardless of results between now and May 2.
Forward Nicholas Bignall returned to parent club Reading on Wednesday due to a groin injury and will therefore not feature.
Midfielder David Bird and defender Alan Wright both remain sidelined with their respective calf injuries, while defender Gavin Caines (knee) remains a long-term absentee.Peterborough manager Darren Ferguson has revealed he is likely to turn to defender Shane Blackett to fill in for injured Tom Williams.Blackett last played for Posh in their home defeat by Southend on February 28 but is expected to be get the nod against Cheltenham on Good Friday following the knee ligament injury suffered by first choice left-back Williams.
The other option for Ferguson is to move Charlie Lee over from central defence but he does not want to disrupt his defence even further.