The Baggies boss admitted that it was 'difficult' to drop the Irish striker but defended his decision after the 1-0 victory over Reading
Long came on after 65 minutes and made an immediate impact when he set up the winning goal against his former club and Clarke praised the 25-year-old's contribution to the team this season.
"Shane has been terrific for me this season and it was a difficult decision to leave him out," Clarke told reporters after the 1-0 victory. "I just thought Lukaku had been very patient waiting for his chance from the bench."
He continued: "I also felt I was always asking Shane to do the horrible shift which is the first hour, where he runs and chases and defenders are still fresh.
"I thought it would benefit Shane to go on as the fresh player for a change, and thankfully, it worked," concluded the Baggies boss.