Manager Dale Sveum said the team would monitor how Jackson swung the bat before Monday's game. With left-hander Dallas Keuchel on the mound on Monday, Jackson wasn't likely to start even if fully healthy. The 24-year-old has made three starts against left-handed pitching since coming up from Triple-A Iowa on Aug. 5.
Right-hander Jordan Lyles gets the ball for the Astros on Tuesday, a more likely situation for Jackson to make the lineup.
"We'll probably get him out early and see if he can go tomorrow," Sveum said.
Jackson, the Cubs' No. 3 overall prospect has appeared in 31 games and made 29 starts in center field for the Cubs, entering Monday's game. He was batting .191 with a .404 slugging percentage in 94 at-bats.
Joe Mather has started the last two games in center field.