Garza came out of his last start after three innings with cramping in his right triceps. He could still be put on the disabled list, retroactive to July 22, which would allow the Cubs to call up a pitcher from Triple-A Iowa for Tuesday's game, such as Casey Coleman.
"We'll have somebody waiting in the wings," Sveum said. "We just have to decide who it is."
Garza didn't get much work done this week as he was with his wife, who gave birth to the couple's fourth child, daughter Summer Grace, on Tuesday.
"It felt like I thought I would feel," Garza said of Friday's workout. "I took three days off and didn't do anything. We'll come back and do it again tomorrow."
He was so busy with his family that Garza wasn't paying attention to Tuesday's Trade Deadline. A few teams had considered the right-hander.
"I was knee-deep in wait," Garza said about being with his wife. "Just wait, wait, wait, epidural, hold, wait, wait, hold, time, where are we at? Three o'clock [Central Time] came and I didn't know [the Trade Deadline had passed]. We looked up and [my wife] said, 'Hey, it's 3:05.' I looked to see if anybody had moved.
"I figured I wasn't [going to be traded] just because of the situation and I hadn't thrown for a number of days," Garza said. "If you traded for me, you were kind of getting a blind pick. That's the way people felt. It is what it is, and I'm happy to be where I'm at and happy to still be playing."
He was more optimistic about starting Tuesday.
"I'm going to try to make it," Garza said. "That's my shot, that's my goal right there."