Pools named just five substitutes for the second game running after a number of late injuries which continue to plague the squad.
The trio added to captain Nicky Featherstone and striker Joe Grey who have missed each of the last three games through injury.
Nelson was handed a slight boost with the returns of Jamie Sterry and Timi Odusina but the injury concerns continue to trouble Pools as their end of season struggles show no signs of letting up.
And Nelson believes the timing of so many injuries throughout the squad can be put down to bad luck more than anything else as suggestions continue to be made about players easing off in the closing stages of the season.
“It’s a really bad spell at the minute with injuries and there’s some different ones,” Nelson told The Mail.
“When Jamie Sterry missed it was a rib injury purely off a contact. Neill Byrne just rolled his ankle in training with no one really near him so it’s nothing to do with any sort of physical state he was in, it’s just bad luck.
“Some of them are muscular which you could put down to fatigue,” he added.
“But some of them have been knocks or contact injuries which can just be bad luck really and you can get anytime.
“It’s unfortunate that they seem to have all come at the same time but it's something you have to adapt to and cope with.”
Pools will have another week on the training ground before their penultimate game of the season at Scunthorpe United this weekend and will hope to welcome back manager Graeme Lee from his spell out while suffering with COVID-19.
But the Pools boss will be hoping for some positive news on the injury front including the likes of Liddle and Morris who Nelson revealed were not risked against Swindon.
“Gary had a tight calf on Thursday,” said Nelson.
“He trained during the week and his calf tightened up with a slight strain and it’s a difficult one where you maybe could have risked him but you could end up damaging him for six to eight weeks which wouldn’t be fair on him so he was a one we erred on the side of caution of.
“Bryn got a knock on Monday. He trained this week but then it flared up again and, again, we just erred on the side of caution with that one as we could have made it a lot worse by having him in.
“We could have put them on the bench to fill the bench but then why if they’re not right?
“Why have them on the bench if they’re going to sit there with the aim of not bringing them on? It just poses more questions as to why you’ve got them on the bench, so we just thought we’d do right by the players and look after them.”