Soriano strained his right calf in the first inning against Cincinnati on April 15 after making his familiar hop to catch a fly ball. The Cubs were 9-5 without him in the lineup.
Soriano struggled in the early season, batting only .175 (10-for-57) with two home runs and five RBIs in 13 games.
"He's ready to go," manager Lou Piniella said.
He said Soriano showed the team he was good to go by shagging fly balls, running the bases and taking extra batting practice. He said the Cubs would not take any undue chances with Soriano but would expect him to steal a base, if necessary.
"We'd like for Soriano to come in nice and hot and give us a lift. We'll see," Piniella said.
Reed Johnson, who had filled in as a leadoff hitter while Soriano was out, was batting eighth in center field for Thursday's finale of a three-game series against the Brewers.
To make room for Soriano on the roster, the Cubs optioned outfielder Matt Murton back to Triple-A Iowa. Murton had been recalled April 19 and was 3-for-14 (.214) with four RBIs in eight games with the Cubs.