The ex-Wigan Athletic forward struck against MK Dons this week.
"You can see from some of his runs that if you spot him and give him the ball, he can create chances and score goals," Sidwell told fulhamfc.com.
"Hopefully he's going to settle in very quickly. You could probably say we were a bit light up front before pre-season but with the players we have now it's not a problem.
"Petric has scored five times in the friendlies and then Hugo's come in today and scored as well.
"Now it's up to the rest of us to chip in with goals."