Gailey provided the update after practice Wednesday, shortly after Wang was spotted walking with only a slight limp entering the team's training room.
"His injury was not as serious as we first thought," Gailey said, according to the Bills' official Web site. "It looks like he could be back by the last minicamp (June 23-25)."
Wang, a fifth-round draft pick out of Virginia Tech, was hurt Saturday during a collision while pass-blocking. Wang couldn't put any weight on his left leg and eventually was carted off the field.
Wang, who will compete for a backup job, is the first player with direct Chinese ancestry to be selected in the NFL draft.
The Associated Press contributed to this report.