Bonifacio, who has led off all but 11 games this season, went on the disabled list Friday with a right oblique strain.
Heading into Monday's game, Valbuena is 2-for-8 as the leadoff man. In his last 26 games, he was batting .360 with 11 doubles, three homers and 10 RBIs.
"We'll see how he handles it," Cubs manager Rick Renteria said of Valbuena.
The Cubs' other options include Junior Lake, who is 2-for-13 batting first and has a .268 on-base percentage overall.
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.