"If all goes well, he'll go to [Triple-A] Fresno," Giants manager Bruce Bochy said.
Bochy said Sandoval reported some soreness after his right-handed swings, but said Sandoval would take more right-handed swings before San Jose's game Monday in Stockton.
After injuring his wrist May 2, Sandoval began his rehab assignment Saturday and has gone 3-for-9 in two games at designated hitter, including a home run and double Sunday.
The switch-hitting Sandoval has been hitting exclusively left-handed as he continues to strengthen his wrist.
Bochy said that ideally Sandoval will return to the Giants for the weekend series against the Rangers, but also said next Tuesday's series opener at home against the Astros could be a better option because of next Monday's off-day.
"That could make more sense," Bochy said.
Joaquin Arias has been a strong defensive replacement to Sandoval for the Giants, and Bochy said the Giants will need Sandoval to return to a strong enough condition to be an everyday starter at third base.
"We need him in shape to play third," Bochy said. "Hopefully we're not forced to make a change. That's in Pablo's hands."
In other injury news, closer Santiago Casilla was scheduled to throw on flat ground Monday after tossing easy catch Sunday.
Casilla has been out since he bruised his tibia in Friday's 4-3 win against the Cubs.
Bochy said before Monday's game against the Cubs that Casilla would be evaluated after the throwing session and could possibly be available for Monday's game.
Reliever Dan Runzler (strained left lat muscle) will throw a simulated game, and Brad Penny, who is waiting to begin his Minor League assignment after spending time in extended spring training in Arizona, has been shut down for the time being with shoulder soreness.
Jay Lee is an associate reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.