Roberts will fly back to Sarasota on Friday.
"Everything went well today," Showalter said. "Very positive. The doctors felt good about getting it done after getting in there. It will speed up the process. I've got marked off what X-number of weeks is from today, so we'll see what happens."
Roberts is expected to endure a six-week recovery period following the surgery.
"He's very determined. He's not going to give in," Showalter said. "That's why it makes me feel confident that he'll come back and be a contributor. We think he's worth waiting on. It's been tough on him. It would be kind of selfish to say it's tough on us. It's tougher on him. If you put yourself in the position he's been in the last two or three years and ask yourself sincerely what you would do ...
"I know a lot of people are being sarcastic about what he's getting salary-wise, and I understand how that works, but we look at it from a baseball standpoint. He's a baseball player that wants to play baseball and be here and contribute with his teammates."
Miguel Gonzalez, placed on the 15-day disabled list today retroactive to May 4, will accompany the team to Minnesota and throw a bullpen session before starting his injury-rehab assignment at Triple-A Norfolk or Double-A Bowie. He threw only fastballs in today's session, with a bandage covering the blister on his right thumb.
Gonzalez is eligible to return May 19.
"We feel confident doing it this way that we can hopefully put it behind us and get him ready to make that start. He's really missing the equivalent of one start," Showalter said.
"I just think this is the most prudent thing to do. I don't care what happened today, he's still going to be tentative throwing is breaking ball and his split. If it forms again, you're going to have a season-long problem, so we just decided to get that done before he had the work day and get that out of his mind.
"He's down to some pretty raw skin there. We got the inflammation out, about half of it, but the other half is still pretty red and inflamed."
Showalter isn't ready to announce his Saturday starter, but Steve Johnson is expected to be recalled from Norfolk. Official word could come later today.
Nate McLouth has stolen 11 bases, putting him one behind the Red Sox's Jacoby Ellsbury for the American League lead. McLouth is on pace to steal 52, which would be the third-most in Orioles history behind Luis Aparicio (57 in 1964) and Brady Anderson (53 in 1992).
The Orioles have won four straight games for the first time since Sept. 26-30, 2012. The last time they won as many as five in a row was Sept. 16-22, 2012, when they won six straight.
Jim Johnson picked up his 85th career save last night. If he gets 21 more this year, he will move into second place on the Orioles' all-time list ahead of Tippy Martinez (105) and Stu Miller (100). Gregg Olson holds the record with 160 career saves.
Left-hander Zach Britton threw 96 pitches, including 54 for strikes, in 4 1/3 innings today in Norfolk's 7-3 win over Buffalo. He allowed three runs and five hits, walked four and struck out six.
Jonathan Schoop was a late replacement for shortstop Yamaico Navarro at shortstop and hit his second home run. I'm told that Navarro was given a day off. No intrigue.
Travis Ishikawa went 2-for-4 with a double and two RBIs and extended his hitting streak to 12 games. He's batting .290.
Note: The start of tonight's game will be delayed because of weather activity in the area.
The tarp is unrolled and the grounds crew is standing in a line, waiting for the rain to arrive.
Update: The Orioles announced an anticipated start time of 7:35 p.m. Still no rain.