Adelaide United are close to handing Korean midfielder Shin In Sup a permanent deal.

The 20-year old has been trialling with the Reds for the past week and will play in tomorrow night's pre-season friendly against Perth Glory at Hindmarsh Stadium.

Coach Aurelio Vidmar said Shin would have to perform well in the match.

"He (Shin) has been quite impressive over the past week so hopefully he can have a good game tomorrow night," Vidmar said.

"We'll see how he goes in the game and then make a decision (on whether we sign him) in the next couple of days."