No logia meaning he can't go into his phoenix form at all or no logia meaning that he's tangible at all times and he can't regenerate?
Either way, Marco's base durability is good enough for him to tank Akainu's magma fist and Kizaru's laser explosions. Something tells me that Gai doesn't have anything to put him down with (Marco >>> Kisame in durability). Marco is also likely WB"s strongest man and was able to tango with Admiral Kizaru. Something tells me that Marco's gonna kick him to the ground and he ain't gonna get back up.