The 24-year-old, who completed a season-long loan deal from Manchester City at the end of August, has spent the last few weeks on the sidelines struggling with a hamstring injury.
The winger suffered the setback in the 2-1 victory over Manchester United on September 28, hobbling off after just 13 minutes, and he will now have to wait a little longer for his return.
"Scott won't make Saturday," Clarke said.
"He's progressing well but as it’s a muscle injury we're just being a little bit careful. He's definitely out for Saturday."
"The ones who have been out for a little while, George Thorne and Zoltan Gera, have little niggles from the Under-21s game on Sunday," he added.
"We'll go carefully with them. Everybody else available is fit and available."
