Swanson was diagnosed Monday with a Grade 2 left oblique strain, which typically carries a recovery timeline of 4-to-6 weeks, Jesse Rogers of ESPN.com reports.
The Cubs are expected to officially place Swanson on the 10-day injured list prior to Monday's game against the White Sox after he was forced out of Sunday's 11-4 loss to the Cardinals with the injury. Assuming the projected recovery timeline holds, Swanson won't be available until around mid-September in a best-case scenario, though the Cubs are hopeful that he'll be back to full health in advance of the playoffs. While Swanson is out, Nico Hoerner is expected to settle in as the Cubs' everyday shortstop, and Pedro Ramirez could operate as the primary option at second base until Matt Shaw (hand) is ready to come off the IL.