Both players have been the subject of speculation after Celtic were knocked from Champions League qualifying on Tuesday night with a 3-2 aggregate defeat to AEK Athens.
Porto were said to be chasing Ntcham, while Marseille had reportedly stepped up their interest in Dembele and were ready to make a £13.5 million offer.
However, Celtic are keen to make up for their disappointment at failing to break into the group stages of Europe’s premier competition by enjoying an extended run in the Europa League, and see both Frenchman as key to their chances.
Meanwhile, the Scottish Sun are reporting that representatives of Dedryck Boyata have met with the club’s board as both parties are keen to come to an amicable solution to the current situation.
Boyata has effectively downed tools after being refused a move away from Parkhead prior to the English transfer window closing and was absent from the two legs against AEK.