He knows why. The 2012 season is the sixth year of his eight-year, $136 million deal with the Cubs, and Soriano says the money is all that fans see.
"They don't see me as a baseball player," Soriano said. "They see me as the contract. They don't see my heart, nothing like that. That's what it is. I know I have a big heart."
His teammates know that, and they understand that with the mega deal comes higher expectations.
"You give anyone $136 million and unless he's in the top 10 in the MVP every year, he's going to get booed," Cubs outfielder Marlon Byrd said. "It'll be interesting to see what happens with Albert [Pujols] with the money he got [from the Angels]. [Alex Rodriguez] is one of the best right-handed hitters of all time and he was booed in New York.
"Once you get that contract, it happens," Byrd said. "'Sori' is used to the boos and it doesn't bother him. It's all worth it when he gets those cheers, and that's what he loves. When he hits that big home run and goes to the outfield and the entire left field is applauding him and bowing to him, that's what he loves. Boos come with the big market. He played in New York, he knows what that's about."
This offseason, Soriano heard lots of cheers. Because of his generousity, more than 80 kids in the small municipality of Quisqueya in the Dominican Republic go to school. They get three meals a day. They are cared for.
He has invested in Mirqueya's Day Care, a school for children in need. For five years, Soriano and his mother, Andrea, delivered gifts to the school. They would do so on Jan. 6, which was Andrea's birthday. She passed away one year ago.
Last May, Soriano hosted a group of children and their mothers from the Connections for Abused Women and their Children (CAWC) in the Chicago area at a Cubs game at Wrigley Field. Volunteers also were on hand to collect donations, as well as distribute informational materials about the Alfonso Soriano Family Foundation and Mirqueya's Daycare.
He also inspires the young players at the Cubs' academy in Boca Chica. For more than a month prior to the start of Spring Training, Soriano is at the facility at 8 a.m. He's there to prepare for the upcoming season and also counsel the prospects who hope to someday have the nice house and cars and lifestyle that Soriano has.
Cubs manager Dale Sveum has heard about Soriano's work ethic. He's also heard the boos directed at the left fielder.
"He's a guy who still put up 28 home runs and drove in almost 90 runs," Sveum said of Soriano, who hit 26 homers and drove in 88 runs in 137 games last season. "You need that kind of bat in the lineup."
Does Soriano still fit?
"Definitely," Byrd said. "The reason for that is because you need veteran presence on the team. [Fans] know the name and forget the things he's done in the game. Sori's not going to be a 40-40 man and everybody knows that, but he can still swing a bat, he can still put up 30 home runs. He hit 26 last year and I don't think he had 500 at-bats. Let him go out there, let him play, let him be Soriano, let him be comfortable and he'll hit you 30 [homers].
"Everything else is cake with him. If he gives you a .280, .300 average, that's a plus. Thirty home runs will give you at least 70, 80 RBIs. If he's hitting in the four-hole, five-, six-hole and we're getting on base like we're supposed to, it's 100 RBIs for him. He does fit."
The Cubs don't have many other power options this season. They're waiting to see how Bryan LaHair does after hitting 38 homers at Triple-A Iowa, to see if Ian Stewart can bounce back and slug 25 like he did in 2009.
The plan is to play Soriano every day, but also give him days off, especially day games after road trips. What about critics who think Soriano is lazy?
"The guy works his butt off all the time," Sveum said. "There's no doubt the fans lost a little faith in him sometimes with the things he does, but I think the fans have to understand he's probably the hardest-working guy in the clubhouse. That's always refreshing, and players love him to death.
"He's the most prolific guy in our lineup and he's done it before," Sveum said. "He's a big part of this lineup and he has to produce."
Sveum hasn't revealed his lineup yet but did suggest he'll probably insert LaHair into the cleanup spot, although he also may test Soriano there.
"Wow," Soriano said at that news. "I'm ready for anything. I just want to stay healthy and do my job."
Another criticism is Soriano's defensive play. He has a tendency to watch balls as they go past him in the outfield.
"I've seen people do it before," Sveum said. "Billy Hall had a habit of doing it, too, in Milwaukee. It wasn't that he didn't play hard, but it was almost a habit. Then they feel bad after they do it, but unfortunately it's a weird habit some people have. Deep fly balls, as hitters, you're like, 'Oh, man, I think I got it, I think I got it,' so you didn't run as hard as you should have."
Bad habits are hard to break.
"You talk about it, and hopefully in that spur of the moment, he thinks about something I said," Sveum said. "A lot of things are tougher than just talking about."
"I know people question his defense," Byrd said. "People are going to question whether his legs are going to hold up. But at the same time, we have an unbelievable outfield coach now, and the little things Dave [McKay] is teaching will help simplify his game and will make him better.
"The stuff we're going to do during the season will make [Soriano] better," Byrd said. "Hitting-wise, everyone knows he can hit. I think he needs those consistent at-bats. He needs four at-bats a game. Yes, he fits. We're going to build this team with him in mind, and that's what they're doing now and he's ready. He's going to be fine this year."
Told that Sveum complemented his work ethic, Soriano smiled.
"Everybody knows," Soriano said. "They know the little things. ... Fans, they see the negative things but they don't see the other way. It's part of the game and that doesn't bother me."
Carrie Muskat is a reporter for MLB.com. She writes a blog, Muskat Ramblings, and you can follow her on Twitter@CarrieMuskat. This story was not subject to the approval of Major League Baseball or its clubs.