They now trail their rivals by 10 points at the top of the table, though Rangers do hold a game in hand.
As a result of their recent poor form, Commons feels this Thursday's Europa League meeting with Braga will take on extra significance.
He wrote in his column for the Daily Mail: "Stopping Celtic's march to nine in a row was always the priority, but the wheels have come off that particular wagon quite spectacularly.
"If they then go and follow that with a weak European exit, particularly if they were to suffer a heavy aggregate defeat over the two legs, it would pile the pain on Gerrard.
"For their season to unravel so dramatically for the second season on the spin, there is a sense that Gerrard is surviving purely on reputation at the moment.
"If it wasn't such a high-profile figure in the hotseat, it would be getting to the stage now where fans would be hounding him out of the door.
"There's a lack of ideas in this Rangers team. They have become stale and one-dimensional. So, in that sense, a return to the European arena may offer them a chance to rediscover their spark."