Kimarnock manager Steve Clarke has accused the SFA of "inconsistent" decision making after Kris Boyd lost his appeal against last week's red card against Aberdeen.

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

Clarke, who was handed a suspended two-game touchline ban for criticising the SFA's disciplinary process early in the season, said: "I have to be careful what I say because I have a two-game suspended sentence hanging over my head.

"I think I said everything I had to say in August, I think what I said in August has been borne through the whole season and I think this is just another example.

"Inconsistencies over decisions on the pitch and inconsistencies on the appeals process - it's very difficult to work out."

And the 55-year-old Clarke, who has taken the Rugby Park club to the cusp of their best league season in years, says it is the footballing authorities and not club managers who need to lead changes.

"I'm not sure why all the onus has been put on to the managers to change things," he said.

"It's up to the authorities, the referees and the referee association and people that are 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 so they should change it.

"You can try and affect change but unless the people at the top want to make the changes then nothing will happen."

Clarke also confirmed Kilmarnock will invest in a new artificial pitch, after ruling out a return to grass on cost grounds.

He said: "There was some consideration to change back to grass until we looked at the bank balance and decided that astroturf was probably the best way forward."