Williams recently conceded that he may have to leave the club in order to find regular first team football, and with the 20-year-old admitting that Swansea City are showing an interest, Palace supporters have become concerned they may lose the midfielder.
Boss Tony Pulis preferred to deploy two defensive midfielders last season, which has raised concerns that Williams does not fit into the manager's favoured system.
However, Issott believes Williams can play in any system, but he needs to establish his best position quickly to have the best chance of developing as a player.
Issott said: "Jonny is very adaptable, he can be a success in any style really and he only plays one way, which is at 100 per cent.
"Maybe at the minute he's just still looking for his best position, he is so adaptable and versatile.
"If he can learn his best position in the next couple of years then he can establish himself in the first team.
"Certainly playing in a midfield is something he can do. He played the majority of time either wide left or wide right, and there are times for Wales he has played behind the striker.
"Jonny needs to see the best route into regular football and flourish more. It can be dangerous if you play too many positions."
The former Tottenham and Stevenage coach stressed the importance for Williams to play regular football, and he also heralded the international's development following his performance in Wales' 2-0 defeat to the Netherlands on Wednesday night.
"It's very important for Jonny to play games. He turns 21 next year and there are obviously a lot of things he wants to achieve and prove to himself, but he's only going to do that playing first team football.
"It's great for him to be playing international football, he's not played as much domestic football as he would like this year, and Wales is very important to him.
"They identified him very early and they adored him from a young age group, he's done fantastically well."