Darnell Fisher and Andrew Hughes were casualties from Saturday’s 2-1 defeat to Birmingham at Deepdale.
Both suffered hamstring problems, left-back Hughes by the looks of it to a greater extent than Fisher.
However, while Fisher’s problem seemed to be cramp, it came in his first game back after more than a month out with a pulled hamstring.
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PNE manager Neil is never one to reveal his hand when it comes to injuries.
When asked whether the full-back pair would be a concern, his reply was ‘probably’.
Hughes was a passenger for the last 15 minutes of the Birmingham game.
He clutched the back of his leg moments after North End had made their final sub of the game, bringing Emil Riis on for Jayden Stockley.
That change had been delayed for a couple of minutes after Declan Rudd had needed treatment on his right knee.
Rudd, incidentally had a precautionary scan on the knee on Sunday which came back all-clear.
Neil has various options for the full-back roles if Fisher and Hughes are ruled out.
Joe Rafferty came off the bench to replace Fisher on Saturday.
If Fisher’s problem was limited to cramp only and does recover, Rafferty could play at left-back.
However, Josh Earl would be a naturally left-footed replacement for Hughes.
After spending last season out on loan at Bolton and Ipswich, Earl is back to try and establish himself in the squad.
His one game this season was the Carabao Cup first round win over Mansfield.
Earl, 22, who signed a new contract last week, made the bench for the Millwall game but wasn’t used.
Neil said: “To a point we have cover but we are not bursting with it. We’ve got some options.”
If North End were to lose Fisher again, that would be a blow.
Of all the club’s full-backs he offers the most going forward – Neil wants to see more attacking thrust from the full-back areas.
With regards PNE’s other walking wounded, Ben Davies and Ben Pearson haven’t played since the home defeat to Cardiff.
Pearson hurt his groin in the closing stages of that game and Davies hurt his ankle.
Neil hopes to be able to include one of them in the squad for Reading, but wouldn’t say who.
Davies’ ankle injury having been described as a ‘knock’ previously by Neil might suggest it is him who is closer to a return.