i read earlier that he must clear waivers first, then he's offered back to Philly, and if they decline, we can outright him to AAA.
maybe RR has jumped the gun in saying he's been sent back, or maybe the waiver process is completed the past couple of days. FWIW, the Nats transactions page now list Vivas for Linan but does not have the McGarry move.
CAmerato reports the DFA and speculates this means Vivas takes Tena's spot. Maybe McGarry's DFA is to create a spot for Perez? Eventually the Nats need another spot.