My understanding is that big signing is planned on RW position. Something like of Tonali or Isak calibre.
In that case Minteh is considered too good for the bench and not there yet to be a starter.
So, the appeal to cash in on him, making quick 30 mln, adding 80-100 to FFP is just too much to resist.

Not that I want him to be sold, but a good deal outside EPL, with sell on and/or buy back clauses is might be the smartest decision.