The Bhoys dropped more points on Saturday afternoon when they were held to a 0-0 draw at Celtic Park and now sit 20 points behind Rangers while having played two fewer games.
Hartson is sure that the league title is gone and does not expect Celtic to catch Rangers.
He believes that any fans saying the opposite are deranged as the gap is now too big to be bridged, with the focus instead needing to be on making sure Rangers do not clinch the title before the split.
“I said it was an awful long way off before the lads jetted off to Dubai”, Hartson said on the Celtic Ten10 Podcast.
“But listen, it’s gone now.
“The league is gone and I think anybody who says that it’s not, I think they’re a bit deranged.
“As you can see, Rangers have lost no games all season.
“If anything else I think Celtic have to be careful they don’t lose the league before the split.”
Celtic had been looking to enjoy an historic season by winning a tenth league title in a row, but are now battling to make sure they can get as close to Rangers as possible to apply some level of pressure.
Rangers are in action on Sunday at Fir Park against Motherwell.
