Van Slyke has been on the disabled list since May 31 with a strained rib muscle in his back. A corresponding move will need to be made.
Mattingly said the other three players that appeared with Van Slyke on rehab stints Monday -- relievers Paco Rodriguez, Joel Peralta and Brandon League -- also had good reports. Rodriguez will continue his recovery from an elbow spur, League (right-shoulder impingement) was pitching back-to-back Tuesday night and Peralta (pinched neck nerve) would continue his rehab later this week at Triple-A Oklahoma City.
Mattingly said reliever Pedro Baez (strained pectoral muscle) would either throw a bullpen session at Dodger Stadium this week or go straight to a rehab game.
Mattingly also said Cuban infielder Hector Olivera was removed from Monday night's game and was held out of the lineup Tuesday night because of altitude sickness at Colorado Springs.
Ken Gurnick is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.