The No. 3 overall pick has not practiced since Aug. 30 due to a hamstring injury.
Bosa missed training camp and all of the preseason in a protracted holdout over his rookie contract. He finally signed his deal on Aug. 29.
The Chargers said they would not rush their first-round pick back on the field. The team wanted Bosa to practice in pads before he participated in game action.
Wednesday was the first step. The last time he'd donned pads was New Year's Day in his final game with Ohio State.
Whether or not he'll be healthy enough to take the field Sunday against the Indianapolis Colts' high-powered offense remains to be seen. If Bosa dresses, it's likely he'll be eased into the rotation.
San Diego could use Bosa's playmaking alongside stud Melvin Ingram in the defensive front. The Chargers boast a stingy corner trio of Jason Verrett, Brandon Flowers and Casey Hayward, but could use depth up front to help get after the quarterback. San Diego has compiled five sacks and given up an average of 400.5 yards of offense (T-23rd in NFL) in the first two weeks.