I think like AA, Greg is as good as retired. Is he down to play any further tournaments this year? I know he wants to play a last DC home tie, but I can't see him battle all the young shots to get back up to a ranking that will allow him access to decent competitions. Why would he bother...?
Greg isn't down to play any other tournaments this year apart from the Aberdeen Cup. He wouldn't make the qualifying cut for any of the TMS events and he wouldn't be seeded in qualifying for some of the ATPs.
I think he just plans to keep himself fit enough to play 1 last DC tie next spring and then either retire [or maybe fittingly end his career during the grass-court season with maybe an Agassi-like farewell at Wimbledon ]