Johnson has started 42 of Chicago's 69 games, and should be playing more after Alfonso Soriano was injured earlier this week.

Soriano was hitting .283 with 15 homers and 40 RBIs when he broke his left finger on Wednesday, an injury that will keep him out for at least a month.

Eric Patterson and Ryan Theriot were 1-for-9 in the leadoff spot in the first two games in place of Soriano, and the Cubs (44-25) had scored just five runs combined.

Manager Lou Piniella decided to try Johnson at the top of the order in an attempt to spark the offense on Saturday, and the move paid off. Johnson hit a three-run homer off Toronto ace Roy Halladay in the second inning, and that was all Chicago would need en route to a 6-2 win.

"It had to feel good for him," Piniella said of Johnson, who earned a standing ovation before a pinch-hit at-bat on Friday. "It felt good to me."

Johnson has 31 RBIs in 171 at-bats after driving in 14 runs in 275 at-bats all of last season.

"To know that there are other teams out there that are interested in you, especially one of this caliber ... it's just really no better feeling than being in Chicago," Johnson told the team's official Web site.

Another former Blue Jay will be on the mound Sunday for the Cubs. Ted Lilly, who went 37-34 with Toronto from 2004-2006, has rebounded from a tough start to 2008, which he began 0-3 with a 9.16 ERA.

Lilly (6-5, 5.13 ERA) has gotten it together of late, going 6-2 with a 3.88 ERA. He went 6 2-3 innings on Tuesday, allowing three first-inning runs and striking out eight in a 10-5 victory over the Braves.

"You just feel like you're never out of it as a starter," Lilly said. "If we can limit the damage, we're going to be in every ballgame."

The Blue Jays (35-35) have limited the damage from opposing lineups all season - their 3.45 staff ERA is among the five best in the majors - but they're a .500 team because of a lack of production from their lineup.

Only two AL teams have scored fewer runs than Toronto's 280. The Blue Jays have scored just 11 runs in losing three of their last five.

Their RBI leader - Vernon Wells (27 RBIs) - is questionable for Sunday's series finale. Wells, who spent nearly a month on the DL earlier this season with a broken wrist, felt some discomfort in his hand on Saturday and left in the eighth inning.

"I sometimes feel it when I'm out in front of pitches," Wells told the Blue Jays' official Web site. "The strength is good and everything else is good, so I'll just try to get back in there tomorrow."

Toronto will turn to Jessie Litsch (7-2, 3.42) in a bid to avoid its fifth straight series loss.

Litsch didn't get a decision as he allowed two runs over six innings on Monday in a 3-2 loss to Seattle, but he's struggled with his command over his last two outings - giving up 20 hits in 11 1-3 innings.