The former Chelsea player is again enjoying learning from Clarke, who he also worked under at Stamford Bridge.
"It was a massive win for us - we needed that," said Sinclair to the WBA website. "It's great that we got the three points, now hopefully we can bounce on and get a few more wins.
"We went 1-0 up, got confidence and built on that. Obviously I knew the manager from my Chelsea days.
"I've come here under him and it's great to learn off him and just be playing very week.
"I'm taking every step as it comes."