ChronicleLive says while Liverpool have apparently moved on from trying to sign Isak, the Swede is still training away from Howe's senior squad.
Howe insists morale is a crucial part of his squad and won't tolerate anyone affecting it.
He said: "I think the group has been disrupted, of course, but I think whenever you have a player in this situation, it's unsettling for the team.
"I don't think we've been in that position since I've been here, the harmony and togetherness of the group has been at its highest, so I think naturaly it's just been a topic of conversation, it's been a distraction and the biggest hit we've taken is we're not blessed with a number of players in his position, so I think you've seen a big gap.
"But I have to say, big credit to the players because they've got on with their work, training has been of a really high level.
"I haven't seen a negative output on the pitch, but I have been aware of feeling around the group that there's something there that's not to the benefit of the group."
Asked if Isak could make their opener against Villa, Howe added: "I don't see that changing before Aston Villa, the current situation we're in."