Wood, who will be making his Cubs debut after being acquired in an offseason trade with the Reds, will be added to the active roster on Sunday morning. A corresponding move will also come at that time, Sveum said.
Garza had already been scratched from his original start, on Saturday, because of a flu virus that has been making its way through the Cubs clubhouse. Sveum said the Cubs will skip Garza's turn in the rotation, with the right-hander tentatively slated to start the series opener in Milwaukee on May 11.
Wood, who arrived at Wrigley Field prior to Saturday's game, said he's felt good at Triple-A Iowa, where he was 1-3 with a 5.08 ERA in five starts. He also said he's straightened out the issues that plagued him during Spring Training, when he allowed 17 earned runs in 14 1/3 innings.
"I fell better," Wood said. "I'm more relaxed; pitches are working. I'm able to command the fastball, and my offspeed [pitches] are working. Everything's feeling good right now."
Wood's future with the Cubs could be longer than just one spot start. After removing Carlos Marmol from the closer role on Friday, Sveum said left-handed reliever James Russell and righty Rafael Dolis would be his go-to relievers in the ninth inning. Russell is the only lefty in the Cubs bullpen, which could cause matchup problems if the club needs a big out against a left-handed batter early in a game.
Sveum said before the game that the lack of an extra lefty in the bullpen had nothing to do with the decision to start Wood on Sunday, and while Wood said the start is a chance for him to show what he can do, he's simply looking to pitch well and give the Cubs a chance to win.
"Most of all, big game tomorrow," Wood said. "We win, we take the series. So hopefully I can go out there and give them a strong outing, and hopefully we win it."