It was the triple substitution which was the chief Cheltenham talking point for Pompey fans.
Steve Allen has now expanded on why Ricky Holmes and Andy Barcham were brought off.
Together with Patrick Agyemang, the trio made way in the 77th minute with the Blues in a comfortable 2-1 winning position.
Ryan Bird, Shaun Cooper and Romain Padovani were thrown on as replacements.
Pompey went on to concede a 92nd-minute equaliser as Jermaine McGlashan netted his second goal of the game.
Inevitably the substitution was widely questioned afterwards by supporters.
Guy Whittingham told The News on Monday the move had nothing to do with shutting up shop.
His assistant manager and physio, Allen, has now explained their exits in detail.
He said: ‘Unfortunately Ricky sustained a direct impact on his calf and resulting from that he had to be substituted.
‘That injury meant he was unable to train on Monday, having treatment instead.
‘‘Although he was back out there with the team on Tuesday. Andy was violently sick at half-time in the toilets in the dressing room.
‘He decided to carry on but we monitored him and got the message from the pitch that he was struggling so had to come off.
‘Andy has been a bit under the weather since.
‘With Pat there were no problems, he has undoubted quality and put in a strong shift for 77 minutes.
‘It’s a hard job up front on your own.
‘He was not injured but since then has had a swollen ankle from a kick and we expect him back in training soon. For me it was a real shame Andy and Ricky were unable to continue.
‘Because those two, together with Jed (Wallace), really have the ability to take the team up the pitch with their direct running with the ball.
‘That’s not an opinion but the facts of why they came off.’
Meanwhile, Chris Dickson is expected to link up with Pompey for training today.
The former AEL Limassol striker featured in a development group match against Leyton Orient on Tuesday.