Trainer Gary Portelli remains mystified as to how the pain killer Ibuprofen ended up in one of his horses but will wear the $3000 fine, reduced from $6000 on appeal.

Portelli said the only explanation was transfer from human to horse and he had tightened procedures for his workers.

Za Magic was found to have the substance, a non-steroidal anti inflammatory, in his system after he finished ninth at Rosehill on September 13.

Portelli appeared before the Racing NSW Appeal Panel on Monday and said he had a fair hearing.

"There is no way of knowing how it got into the horse's system because it is not something we use on any of our horses," Portelli said.

"The only thing we can think of is that one of the staff took a Nurofen Zavance which has Ibuprofen in it.

"Maybe someone has accidentally dropped a tablet or they had the substance on their fingers after taking one and then went near the horse.

"From now on all the stablehands have to disinfect their hands when they get to work.

"The horse ran ninth so it wasn't as if it made a difference."

It was the first such offence of Portelli's 23-year career.

Portelli will now turn his attention to the track. Among his runners on Saturday is debutante Hey Good Looking in the two-year-old Plate.

"She is a lovely filly to work with and has done everything right so far," he said,

"I think she will be better later on but she is up and running now so we'll start her off on Saturday."