Monday will give the first indication, as he will do some light throwing.
Along with Fernandez, reliever Carter Capps (right elbow strain) continues on his throwing progression. When the hard-throwing reliever went on the disabled list on Aug. 3, the hope was he would be ready after just 15 days.
Capps would be eligible to be reinstated on Monday, when Miami opens a three-game set at Milwaukee. However, his target date will be at least a few more days away.
Before Capps is reinstated, he is expected to pitch in a rehab assignment game with Class A Advanced Jupiter.
Also on Monday, right-hander Jarred Cosart, who is on the Minor League disabled list due to vertigo, is scheduled to throw a simulated game at the Roger Dean Stadium complex in Jupiter, Fla.
Cosart, who has been diagnosed with a left inner ear disorder, has been progressing on scheduled. If his sim game goes as scheduled, he could be pitching in a Gulf Coast League game later in the week.
Of the three, Capps is the closest to returning. Next could be Cosart, who may be back before Sept. 1. Fernandez ideally would be ready at some point in September.
Fernandez has made seven starts since he returned from Tommy John surgery on July 2. The right-hander is 4-0 with a 2.30 ERA, striking out 53 in 43 innings.
In his start at Atlanta, he endured a 38-pitch fourth inning, and finished with 76 pitches.
Fernandez has stated that if he is healthy enough to pitch, he plans on taking the mound before the season ends.
Joe Frisaro is a reporter for MLB.com. He writes a blog, called The Fish Pond. Follow him on Twitter @JoeFrisaro and listen to his podcast. This story was not subject to the approval of Major League Baseball or its clubs.