"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.