Arsenal have finally got their man through the door in Riccardo Calafiori after weeks of negotiations with Bologna. The Italian centre-back has now joined up with his new teammates in the United States for their pre-season tour. Mikel Arteta was keen for Calafiori to join up with Arsenal during their trip to the States to help the Italy international settle in to his new surroundings. However, there are players at Arsenal who are impressing this summer who were already at the club. And there is one, in particular, who may have just earned himself a big role for the upcoming campaign on the bac…