Speaking on the BBC’s Scottish Football Podcast, Neilson said he had not applied for the post and is happy working in the City Football Group as assistant at Belgian club Lommel SK.
However, he believes Aberdeen should have been prepared for a quicker appointment.
“Whoever comes in now, if it isn’t Horneland, they’re probably going to be looked on as second, third or fourth choice and I think that’s the difficulty of it.” he said.
“I totally understand they want to get the right guy in but in my opinion a sporting director, even when the manager is doing well, should have a list of three or four targets.
“You have to be prepared for success and failure. It’s taking too long.
“You look at the transfer window in January with six players in and nine players out and it’s a another massive turnover after 15 players in the summer. They really need to get a bit of stability.”
Neilson also joked that the weather in the north east, and a particularly rain-soaked spell, might have an effect on the appointment.
“One thing I did see is that the potential manager was over last week. And the time he comes in is in a world record no-sunshine stretch of days.
“If he’s landed on the Monday and not seen the sun by Friday, he might think ‘I’ve got an opportunity in Spain, where am I going?'”
The former Scotland international also says the playing squad will be growing anxious about the length of time without a decision, which has a knock-on effect for the interim boss.
“For Peter Leven it must be very difficult,” Neilson said. “He’s seeing the stuff in the news and then turning up every morning to take the team.
“Players will be speaking about it and he’s trying to get his authority and ideas to the team while players are thinking ‘he’s probably not going to be here tomorrow’. And then he has to take another game, and another.
“They really need to get someone in. If it’s Horneland, fantastic and let’s see how he does.
“But they need someone to come in and take the team and give them direction.”
