CHICAGO -- Cubs catcher-infielder Steve Clevenger was sent for an MRI on his left side after being injured on a strikeout swing to end Saturday's 3-2 loss to the San Francisco Giants.

Clevenger was pinch hitting for pitcher James Russell when he took an awkward swing at Giants closer Santiago Casilla's last pitch. Clevenger fell down and writhed in pain as teammates and training staff came to his aid.

A source said that the first diagnosis by team doctors indicated Clevenger sustained a left oblique injury. The 27-year-old utility man was the team’s third catcher and had added first- and third-base duties to his résumé during spring training. Clevenger started his first major league game at third base Friday and handled three chances flawlessly.

The Cubs will most likely play with 24 players in Sunday's finale with the Giants. The team has an off day on Monday. Second baseman Darwin Barney is scheduled to return from the disabled list Tuesday. Barney is on a rehab assignment at Triple-A Iowa. He has been on the DL since Opening Day with a left knee laceration.