Frazier, 27, has appeared in 10 games this season after the Cubs signed him as a free agent during the winter. He was the fifth overall pick by the New York Yankees in 2013 but had injury issues related to suffering multiple concussions while playing in New York.
"We're keeping him in our thoughts," manager David Ross said.
Frazier has a career .753 OPS in 238 games. He was part of a crowded outfield mix for the Cubs, hitting .143 in 21 at-bats. Now he's out for an undetermined amount of time.
The team had not yet announced a corresponding roster move, as their Friday game against the Pittsburgh Pirates was moved from afternoon to evening because of weather in Chicago.