Arsenal are set for a busy end to the summer transfer window, with one more senior signing set to arrive and several players in line to be offloaded. In terms of incomings, the Gunners have already signed Riccardo Calafiori from Bologna, and they’re now set to add Real Sociedad’s Mikel Merino to their ranks. Arsenal have also been busy on the outgoings front. The Gunners have already let several first-teamers leave this summer, and several more could soon follow. Now, Fabrizio Romano has provided an update on an Arsenal talent who is set to be sold to a former La Liga winner. READ MORE: Whethe…