In other moves Monday, the Orioles optioned pitchers Brad Bergesen and Jason Berken, along with infielder Matt Antonelli, to Triple-A Norfolk and placed left-hander Zach Britton (back) on the 15-day disabled list.
Roberts played in only 39 games last year, none after May 16. He has practiced with the Orioles this spring but has not participated in an exhibition game.
Unlike last year, when the two-time All-Star rehabilitated alone in Florida, he will return with the team to Baltimore next week.
"I really didn't want to be separated again, be down here away from my teammates and kind of not feel a part of things," Roberts said.
He says being on the 15-day DL is an indication that the team expects him to return in the near future. Although there is no timetable, he says, "I have hope that I'm coming back."
Bergesen was 2-0 with a 3.75 ERA in spring training, with 12 hits allowed in 12 innings over five appearances. Last season, he went 2-7 with a 5.70 ERA in 34 games, including 12 starts.
Berken didn't make his spring debut until throwing a scoreless inning on Sunday against the Philadelphia Phillies. He had been sidelined with a strained hamstring.
"I talked to both of them about it and they seem to be upbeat about starting down there," manager Buck Showalter said. "We just feel like we have some people ahead of them right now. Berken got behind the eight ball because of the leg. I hope they pitch well and present options for us as starters. It's not like they're going away. Hopefully, they'll be depth for us and impact our club. That's going to kind of be up to them."
Britton is shut down with left shoulder inflammation.
Showalter stopped short of saying that Rule 5 pick Ryan Flaherty, a utility infielder, has made the club because Antonelli and Tolleson could be brought back. However, Flaherty is likely to win the job.
Antonelli batted .194 in 20 games, and Tolleson batted .286 in 19 games. Flaherty, selected from the Chicago Cubs' organization, is batting .279 with two doubles, two triples, one homer and eight RBI in 18 games.
Hester went 0 for 14. His removal from the camp roster indicates that Ronny Paulino could back up Matt Wieters on opening day.