But he gave up no earned runs and struck out 14 batters in his first seven appearances (eight innings) as a setup man before giving up a Dustin Mohr home run on Saturday against Colorado.
So he is warming up to the role.
"Yeah, whenever you get guys out it's fun," Wood said. "I'm having more fun than I thought I was going to have."
Wood landed on the disabled list twice this season with shoulder problems. He also missed some time during spring training.
The problem is that when he reached the 50- or 60-pitch count mark during starts, he would feel discomfort. He will likely have off-season surgery to clean out the shoulder. But for now, doctors are convinced that as long as he makes short relief appearances, he should be fine until the offseason.
Wood is throwing high-90 to 100 mph heat and has been impressive as a setup man. But the Cubs aren't paying him huge dollars for that role.
"I'm going to rehab and work out accordingly to be a starter next year," he said.