I like Mr. Andrew Murray, OBE. He surely has deserved his moments in the sun.
I think now he is just trying to get some matches under his belt anyway he can. He's played, count them, 6 tour level matches since he left for surgery.
His highest ranked opponent in those matches was ranked #26 - Lopez. I think playing this tournament was a positive for him, even if he loses his next match. He's made it to the QF without too much trouble, and he probably had considered not even playing in the AO at some point. So it is already a plus for him.
I think he has Davis Cup vs. the USA scheduled right after the AO, then Acapulco at the end of Feb. followed by Indian Wells, so I'm sure the first priority is to leave the AO healthy. I don't think he'll risk aggravating anything. It might be a good exit point for him, no? He can travel to the Americas and be ready for Davis Cup and the other following American tournaments.
Respectfully,
masterclass