The left-hander and the team are confident he won't be placed on the 15-day disabled list. Garcia could start early next week in Chicago against the Cubs.
Manager Mike Matheny said the replacement for the opener of a four-game series with the Padres will be a minor league call-up.
Garcia was injured rounding third base scoring a run in the eighth inning of his last start on June 24 in Miami. The team had previously referred to the injury as a groin cramp.
Garcia is 3-3 with a 1.69 ERA in seven starts coming off thoracic outlet surgery to correct a nerve issue in his shoulder that cost him most of the previous two seasons.