He missed a few weeks of action in spring training, then was sidelined two months after leaving a game in late April.
After leaving Wednesday night's game against Cincinnati after three innings with yet more discomfort in the shoulder, Wood wondered if his season would be over.
But Wood received a cortisone shot on Thursday. Even though he will miss a start Monday, he hopes to be fine the rest of the season.
"We got the shot and we're going to be a little more aggressive in the treatment this time," Wood said. "We'll see if that will take care of it."
"The steroid they injected in there is used to decrease the inflammation in the joint," Cubs trainer Mark O'Neal said. "He's getting irritation to the joint when he's throwing. This is an aggressive approach to quiet it down."
Wood, who is 3-3 with a 4.67 ERA, has missed more time than he would like with arm troubles since bursting onto the scene as a rookie in 1998.
After resting the shoulder for the better part of two months, he thought his troubles were over. Then he started feeling tightness again on Wednesday.
"It's frustrating, obviously," Wood said. "I thought I bounced back. I worked pretty hard to get the shoulder to where I thought I needed it to be. To get three or four starts and have it happen again ..."
"I was throwing 87 (mph) fastballs, and I haven't done that in a long time. Everything was fine until the second inning."
The Cubs must evaluate how they will handle Wood after the season. It's possible he will need surgery to clean the shoulder out.