#1 The senior players in the squad expressed reservations about his arrival

Just a year ago, key players in the Barcelona squad including Messi were unequivocal in their campaign to bring Griezmann to the Camp Nou.
However the World Cup winner threw mud in their faces by shunning them and committing to a new contract with Atletico instead.
Just like the fans, this was a slight not taken kindly to by the Barcelona players, with the result being that a massive U-turn was taken about his arrival.
When asked about the potential arrival of Griezmann earlier in the summer, Lionel Messi declined to speak on the matter, while expressly stating his desire to see Neymar return, and the same was the case with Luis Suarez.
The only Barcelona player who came out to publicly support the French international was Ivan Rakitic, with the Croat stating his opinion that he saw the action as a commitment to Atletico rather than a slight on Barcelona.
The reception of a dressing room is integral to how well a player settles into his new team and with key players seeming indifference to his arrival, Griezmann could have a hard time settling in at Nou Camp.