The 24-year-old winger missed the club's previous two games after injuring his hamstring against Manchester United in the Baggies' 2-1 win at Old Trafford.
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"Scott won't make Saturday. 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," Clarke told reporters.
"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. We'll go carefully with them.
"Everybody else is fit and available."
West Brom were winless and goalless after their first three games of the new Premier League season, but have since been unbeaten in their last five matches, which included an unlikely win over the reigning champions.