Preston boss Alex Neil says Daniel Johnson’s absence from the squad for the last two games is down to a head injury he suffered in the Wolves game.
The midfielder was hit on the temple by the ball and had to be substituted in the latter stages of the 1-1 draw a week last Saturday.
Johnson went to hospital after the game to be checked out by doctors.
He missed last Tuesday’s visit to his former club Aston Villa and the weekend’s loss to Ipswich.
Neil told the Post: “He has got cognitive tests through the doctor which he is not up to speed with yet – he hasn’t passed all of them.
“We can’t play him yet, he is not allowed to play.”
Whether DJ will be fit for Saturday’s Gentry Day clash with Bolton at the Macron Stadium remains to be seen.
Head injuries are taken seriously and it needs a doctor to give the all-clear.
Elsewhere on the fitness front, Paul Gallagher was able to return to the bench on Saturday after two games out with a hamstring injury.
He could get a run-out in a behind-closed- doors game on Tuesday to sharpen his fitness.
Said Neil: “We have got a game on Tuesday for the lads who haven’t been playing.
“We will tick them over and get minutes into their legs.”
Neil gave the squad Sunday and Monday off, something he had planned to do irrespective of the Ipswich result.
“I think it is good that they didn’t see each other for a couple of days.
“We have an important run of games coming up and have to make sure they are mentally and physically fresh.
“The Aston Villa game was our second highest running stats this season in terms of how hard we had worked and the two games previous to that we’d played with 10 men.”