Leeds United are currently in 15th place in the Championship table under the guidance of Steve Evans.
Cellino’s trigger-happy approach at Elland Road has caused a sense of instability at the club, with managers changing regularly.
And Clark feels that this insecurity will rub off on the players, meaning that Evans will have a very tough task to motivate them.
"He’s disrespected the supporters, certainly with the last incident [saying he would sell the club to the fans, and then retracting the offer]," Clark said. "He’s moved the goalposts, basically.
"It’s difficult for [Steve Evans] because the players aren’t silly. They’ll know that this guy isn’t hanging around too long, so [they might think] ‘I’ll just keep my head down for a while’.
"It doesn’t give you the stability that is needed at a club."
Evans has made a positive start to his time at Leeds, with the side improving considerably under his stewardship.
The Whites have won back-to-back matches, but Clark’s opinion on Cellino was backed up by his fellow Sky Sports pundit Ian Holloway.
"I don’t understand how someone can say to a group of supporters, after a defeat at home, to get them off your back, that he’ll sell the club and then change his mind," Holloway added.
"He’s letting Leeds United down. The supporters and the town deserve better than that. Sell it out and move out the way, mate."
Cellino insists that he does still want to sell Leeds, meaning that they club’s future is unknown.
They will hope to continue to impress on the field though, and at the moment Leeds are in 15th place in the Championship table.