Yarbrough (groin) threw from 150 feet on flat ground Sunday and has yet to throw off a mound since being placed on the injured list last week, Marc Topkin of the Tampa Bay Times reports.
The 30-year-old was expected to miss only one start after landing on the shelf April 11, but that no longer appears to be the case given he has yet to throw off a mound. Yarbrough apparently hasn't suffered a setback, and manager Kevin Cash hopes the lefty can get back on the mound within the next couple days.