"He just couldn't be the player that he was," Roberts said. "When you're talking about the back and what we have left in the season, we didn't want to put him in harm's way. We have the opportunity to have days backdated, not lose too many days on the calendar, and it just made sense to get him back to 100 percent."
Thompson went 5-for-35 on the recent homestand and saw his average sink to .225, so he also figures to work on his swing while he's out.
Walters, 26, was purchased by the Dodgers from Cleveland in April. Originally drafted by Arizona in 2011, he has played briefly in the Major Leagues for Washington and Cleveland, most recently last year.
"Zach can play anywhere, a switch-hitter, and with a four-man bench, to have the ability to have a player that can play both corner-outfield spots and anywhere in the infield, it gives me flexibility," Roberts said.
While at Triple-A Oklahoma City this year, Walters hit .298 with an .836 OPS, 10 homers and 47 RBIs in 77 games. He credited OKC hitting coach Shawn Wooten with leading to his offensive improvement.
"He just made fun of me that I was raw, had no idea to repeat a swing, and he worked with me and I have an idea what I'm doing now," Walters said. "I can take constructive criticism, something I need. Coming here has been a blessing, especially with him."
Ken Gurnick has covered the Dodgers since 1989, and for MLB.com since 2001. This story was not subject to the approval of Major League Baseball or its clubs.