The Spurs' point guard, who hasn't played since rupturing a tendon in his left quadriceps during last season's Western Conference semifinals, practiced Wednesday in San Antonio with the team's G League affiliate.
It is unclear how many times Parker will practice with Austin. The Spurs, who formally assigned Parker to Austin on Wednesday, say he will work out with the G-League club again Friday.
"He wants to come back immediately," San Antonio coach Gregg Popovich said Wednesday in Miami, where the Spurs are playing the Heat. "But he knows he's got to be prepared for it, be 100 percent before he can come back.