Rangers manager Skip Schumaker said that Jung (calf) was unable to run at full speed prior to Friday's game against Seattle, Jeff Wilson of AllDLLS.com reports.
Schumaker said the Jung was running at "half-speed" as a result of a left calf injury that Jung picked up Tuesday against the White Sox. The injury is severe enough that the veteran third baseman may need a stint on the IL, and Wilson suggests that a decision from the Rangers could come as soon as Saturday. Ezequiel Duran is starting at third base Friday and could continue to see more reps at the hot corner for as long as Jung is sidelined.