The 32-year-old striker has plantar fasciitis, an inflammation of the thick band of tissue which runs across the bottom of the foot.
Evans first suffered it during pre-season training and he has not played since the away game at Huddersfield on August 17.
He had a spell of having to self-isolate after that game, while a knock-on effect of the foot injury was a problem in his calf.
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PNE head coach Frankie McAvoy said: “Hopefully he won’t be out too much longer.
“It’s his foot and it can be difficult with plantar fasciitis, it’s a sore one.
“You’ve got to make sure it’s right and that he’s ready to come back and train.
“Ched has been ill since he last played, that ruled him out for a bit.
“Then he’s had some slight knocks and injuries. When you have an issue with his foot like he’s had, it can cause niggles in other areas.
“You start to feel different things because of the problem in the foot.
“We’ve got to make sure Ched is 100% fit and he is on the right lines.
“We won’t rush him, he’s carrying a painful injury.”
Last season, Evans started 19 successive games from late January through to the end of the campaign after his arrival from Fleetwood Town.
Signed initially on loan, the move was made permanent shortly after the close of the winter transfer window so that PNE didn’t have too many loan players.
Later in the season Evans signed a new two-year deal.
Another of North End’s long-term casualties is much further down the line in his bid for full fitness.
Matthew Olosunde has been back training with the first-team squad for a couple of weeks now.
The summer signing from Rotherham was injured in the second pre-season friendly at St Johnstone.
After Saturday’s 0-0 draw with Derby, Olosunde took part in a training session at Deepdale with those who had been on the bench or weren’t in the matchday squad.
Having missed most of pre-season, the American defender is playing catch-up and building up the fitness normally done in the summer.
Said McAvoy: “Matthew is fit and we’re just getting him up to speed now. After a long-term injury you can’t just throw him straight back in.”
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