Word came out earlier this morning that Lim was dealing with medical issues backstage and it was officially announced on the UFC Macau weigh-in stream that Lim would not be participating in the event.
Ultimate Fighting Championship (UFC) released an official statement regarding the situation:
After being examined by doctors it was determined that Hyun Gyu Lim was medically unfit to participate in tomorrow's event and as a precaution, his UFC Macao bout has been canceled. His opponent, David Mitchell, will be paid his show money.
It is widely believed that Lim was having issues with his weight cut. At 6'2, he is one of the largest fighters on the UFC roster that makes the cut down to welterweight.
Lim's opponent, David Mitchell (who was a late replacement for the event), will be paid his show money for the ordeal and will likely be given a new fight (or perhaps the same fight) soon. On the Fuel TV weigh-in stream, it was revealed that Mitchell was told to stay on weight. This is likely in case another welterweight has issues before the event, which would allow him to step in as an emergency replacement similar to what Charlie Brenneman did back at UFC on Versus 4 in 2011.
With the late change, there are now only three bouts which will be showcased on the preliminary Facebook stream, which is expected to begin tomorrow morning at 7:40 a.m. ET.