HOUSTON -- Center fielder Brett Jackson, out since Friday after he bruised his right knee crashing into the outfield wall in Pittsburgh, could be back in the Cubs' lineup as early as Tuesday.

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.

Sveum impressed with Soriano's surprise season

HOUSTON -- Left fielder Alfonso Soriano's stellar season drew some high praise from Cubs manager Dale Sveum on Monday.

"He's probably the biggest surprise in all of baseball, really," Sveum said. "A lot of people had written him off. Another year older and the legs were another year older."

Soriano entered Monday's game with 28 homers and 94 RBIs, making a 30-homer, 100-RBI season well in reach. The 36-year-old hasn't reached those benchmarks since 2005, when he was a second baseman with the Rangers.

"That would be one of the better stories of the year," Sveum said. "I just thank God that he's put together that year for us, because obviously we haven't been all that productive this year."

Soriano didn't hit his first homer of the season until May 15 in his 120th at-bat. Since that day, Soriano has hit 28 homers, tied for the most in the Majors over that span, entering Monday.

The last Cubs player to hit more than 25 homers despite not hitting one before May 15 was Ralph Kiner, who did it in 1953.

"He's been the one cog in the machine that's been pretty much consistent ever since May 15," Sveum said. "He's been as good as anybody in baseball since May 15."

The Brewers' Ryan Braun, the Angels' Albert Pujols and the Tigers' Miguel Cabrera also entered Monday's games with 28 homers since May 15.

Vitters hopes homer gets him on track

HOUSTON -- Manager Dale Sveum hopes third baseman Josh Vitters gained a little confidence on Sunday after ending an 0-for-27 skid with a solo homer in Pittsburgh.

"He hit two balls right on the screws yesterday, so hopefully," Sveum said. "We're getting quite a few lefties here in the next week, so that will give us a chance to get him some at-bats and see what he can do."

Vitters batted seventh on Monday against Astros left-hander Dallas Keuchel. The Cubs will face left-hander Fernando Abad on Wednesday and probably draw Pirates left-handers Jeff Locke and Wandy Rodriguez this weekend in Chicago.

Ranked the Cubs' No. 11 prospect, Vitters entered Monday's game batting .085 (6-for-71) with two homers and five RBIs. He hasn't recorded a multihit game since making his Major League debut on Aug. 5.

Worth noting

This is the Cubs' final trip to Houston before the Astros join the American League West in 2013. Since Minute Maid Park opened in 2000, the Cubs were 49-51 in Houston, entering Monday's game.