The squad members have been instructed to find new clubs.
Riqui Puig has one year left on his contract and while Barca have not entirely ruled out the possibility that it will be renewed, they want him to leave on a loan deal.
Another player is goalkeeper Neto. The Brazilian has been deputy to Marc-Andre Ter Stegen over the past few seasons.
Defensive pair Samuel Umtiti and Oscar Mingueza have also been told they can find new clubs, with the arrival of Christensen and impending arrivals of Cesar Azpilicueta and Marcos Alonso set to further reduce their chances of first-team football.
Also on his way out is Albanian striker Rey Manaj, who is believed to be on the verge of joining Watford.
Barca’s tour of the US will start on 20 July against Inter Miami in Florida before facing Real Madrid in Las Vegas four days later and then taking on Juventus in Dallas on 26 July. They will conclude their tour of the US with a clash against New York Red Bulls on 31 July.