Roberts said the team is considering getting some tests done, perhaps an MRI, on the 34-year-old veteran's lower back before proceeding any further with him.
Ethier left the game on March 6 with back spasms, and returned with an at-bat on Friday. He went 2-for-2 on Saturday, but on Sunday morning he had to shut it down again.
"For a couple of days we felt he was out of the woods, but then this morning he was in there and was ready to go, but he just didn't loosen up," Roberts said.
• One piece of good news Roberts received when he returned to camp following the death of his father is that Corey Seager, out since March 4 with a strained oblique, is making progress toward a return to Cactus League action.
"I've tried to stay in tune and to see Corey back as a full participant is good, running the bases and taking swings and throwing," Roberts said. "He's on his way. As I understand it, he's hopefully turned the corner, so we'll get him in a game sometime soon."
Roberts later said that, after talking with Seager and watch him go through drills, the slugging shortstop will continue to participate in full workouts the next couple of days before the team's Wednesday off-day, then get some at-bats on Thursday -- either on the Minor League side or in the Dodgers' Cactus League game.
• Roberts said young right-hander Julio Urias was going to be on the mound Tuesday, but that's looking unlikely as he was sent to his spring home with what may be strep throat.
"He'll back hopefully [Monday] and we can kind of gauge his energy and strength," Roberts said.
• With veteran Rich Hill getting his work in a Minor League game, Trevor Oaks made the start against Team Japan and impressed Roberts, as he had already through spring. Oaks, who played at three levels in moving up to Triple-A last season, allowed three hits in three scoreless innings.
• O'Koyea Dickson sent the Dodgers home walk-off winners over Japan with a two-run double the opposite way to the right-field corner, showing off his considerable offensive tools.
"He's got a big-league bat, and he's just got to continue to develop as a defender. But there's a lot to like," Roberts said of Dickson, who has spent the last two seasons at Triple-A.
• Prior to Sunday's game, the Dodgers reassigned catchers Jack Murphy and Wynston Sawyer, right-handed pitcher Fabio Castillo and infielder/outfielder Stetson Allie to Minor League camp. That trimmed down the camp roster to 53 players.