Kilmarnock boss Steve Clarke claims inconsistency continues to bedevil disciplinary decisions in Scottish football following the failed appeal of Kris Boyd's red card at Aberdeen.

The 35-year-old striker was dismissed at Pittodrie last week following his challenge on Dons captain Graeme Shinnie and a Scottish Football Association fast-track hearing upheld the decision, leaving Boyd suspended for Friday's Ladbrokes Premiership match against Hearts and next Wednesday's trip to Dundee.

Clarke was handed a suspended two-game touchline ban for criticising the Scottish FA's disciplinary process early in the season.

In a statement made following a failed appeal against Gary Dicker's sending-off against Hearts in August, Clarke stated that referee Willie Collum had lacked a "calm and rational" approach while arguing that Collum's appointment for a Celtic versus Rangers game had effectively pre-judged their appeal.

"I have to be careful what I say because I have a two-game suspended sentence hanging over my head," said Clarke.

"I think I said what I had to say in August, what I said in August has been borne through over the whole season.

"I think this is just another example of inconsistency of decisions on the pitch, inconsistency on the appeals procedure.

"It is very difficult to work out."

Clarke insists it is the authorities who need to take the lead with regards to making appropriate changes.

He said: "I'm not sure why the onus has been put on the managers to change things.

"It's up to the authorities and referees, the referees' association and the people in charge of the disciplinary. They have to change it, they have to make it better.

"We don't get paid to change it, people get paid to do that, they should change it.

"You can try to affect change but unless the people at the top are going to change it nothing will change."

Killie have the chance to go second behind Celtic on Friday night, but Clarke is expecting "another difficult game against a difficult team".

"The fixture gods haven't been very kind since we came back from the winter break," said the former West Brom boss.

"Rangers at home, Aberdeen away, Hearts at home is a tough run of fixtures.

"Hearts had a great result last week against St Johnstone, who are particularly good on the road.

"Don't forget Hearts were top at the start of the season before they picked up a lot of injuries.

"Those injuries have started to trickle back into the team and I think Hearts will be a force between now and the end of the season."