Rowan will link up with ex-City players Dan Matsuzaka and Harry Kyprianou on the south coast and will be available for the Terras' game tonight against Worthing in VNLS.
Manager Ross Jenkins said: "It's a good move for Charlie, he's a great lad with great ability and ambition. We've got to help the player as much as possible and at the moment he's been starved of minutes.
"We can monitor his performances and make sure he's fit, strong and ready to come back because its only 28-days. He's a big part of this club still and it's important we keep everyone fresh and fit. It's a great move for him."
Good luck Charlie!