"The back strain is one he has had on and off for two or three weeks and maybe it has gradually caught up with him.
"We think the best thing is to check it out now, get to the bottom of it and see where we go from there.
"Bap wasn't quite up to it last Saturday (against Lincoln) but he won't put how he played down to injury.
"He knows he didn't have the best of games, but that could be said of another eight or nine players."