"I am encouraged," Trembley said. "[Roberts is] feeling better, but he's got a ways to go yet."
Roberts played catch on Friday, but Saturday marked the first full day of activities, with Roberts also taking ground balls. Trembley wasn't sure of Roberts' progression following Saturday since he will have to be evaluated by head athletic trainer Richard Bancells before adding anything further.
The Orioles' leadoff hitter, Roberts suffered a herniated disk in his lower back during offseason workouts in Arizona. Following 19 spring at-bats, Roberts was deemed ready to play but reinjured himself on a slide into second base in the April 9 home opener. He was officially placed on the 15-day disabled list on April 12, retroactive to the date of the injury.
To clear a roster spot for Wednesday's addition of Corey Patterson, the Orioles moved Roberts to the 60-day DL, which would make him eligible to return as early as June 10.
Prior to Friday's game, Roberts confirmed to MLB.com that his target date is the first day he's eligible off the DL.