PNE ace Greg's hamstrung by injury
The stand-in skipper felt his hamstring tighten up and was substituted at half-time.
He could be a doubt for the clash with Sunderland at the Stadium of Light on Saturday.
North End manager Alex Neil said: “It was an enforced change with Greg coming off, he was struggling with his hamstring.
“He is a key figure for us but what you have to bear in mind is that in the last calendar Greg has had a broken leg and an horrific hamstring injury.
“In terms of being up to speed and being fully fit he is probably not quite where we would like him to be.
“This was the third game in a week and it seems that his hamstring couldn’t take the load.”
Neil did seem to rule out it being a long-term problem for Cunningham who has been named in the latest Republic of Ireland squad.
“I don’t think it was a tear or anything like that, it just seized up,” said Neil.
“When you are playing against Fulham you need to run, you need to cover ground.
“You can’t sit yourself in a pocket and hope they don’t come towards you.
“It was never going to work for him in the second half.
“That was the reason too why Paul Gallagher didn’t play and was on the bench.
“His hamstring was really tight and he was sitting there about 80% fit.
“But Daniel Johnson, Alan Browne and Ben Pearson had legs and determination in there – I thought they all did great.”
Cunningham was missing for four months earlier in the season after his hamstring muscle came away from the tendon – the same injury Sean Maguire was to suffer.
Cunningham was replaced by Calum Woods for the second half on Saturday, Woods not looking particular comfortable in the left-back role.
If Cunningham does not make the weekend, it could see Josh Earl come back into contention.
It might be that the clear midweek will give sufficient time for him to recover.
On the defensive selection front, Tom Clarke was back on the bench against Fulham.
The skipper had not played since the 2-1 win over Hull City in February because of a knee injury.
Saturday’s game saw Paul Huntington avoid a booking, hence lifting the threat of a ban hanging over him.
He has nine yellow cards to his name but the FA’s amnesty for 10 cautions kicked in after the 37th game of the season.
Midfielder Johnson was in the same boat as Huntington.
Meanwhile, North End have sold more than 1,350 of their 3,000 ticket allocation for the Sunderland game.