Gausman had been receiving treatment for about the past week, but the inflammation was not clearing up as quickly as hoped.
• Orioles Spring Training info
"Once we reached this date and getting closer to the season, we wanted to go ahead and take the precaution of trying to help him get rid of that last little bit there," Showalter said.
Gausman was placed on the disabled list with right shoulder tendinitis in May 2015 and missed more than a month. After returning, he made 17 starts for Baltimore and posted a 4.22 ERA, striking out 90 batters over 100 1/3 innings.
The 25-year-old has made two Grapefruit League starts this spring, most recently going four innings on Wednesday against the Pirates. Before getting the injection, he was scheduled to pitch in a Minor League game on Monday.
• In better news for the Orioles, catcher Matt Wieters threw on Sunday for the first time since hurting his right elbow on March 12. Wieters started at 25 feet and eventually stretched out to 60 feet, with "a lot of intensity," according to Showalter.
"That was encouraging with Matt today," Showalter said. "See how he feels tomorrow."
Wieters returned to live batting practice on Saturday and was taking his cuts on the field before Sunday's game. On Tuesday, when the Orioles go on the road to take on the Twins, Wieters will join Chris Davis, Pedro Alvarez and Hyun Soo Kim in getting "a bunch" of at-bats in Minor League games, Showalter said.
• Right-hander Yovani Gallardo is scheduled to pitch in a Minor League game on Monday. Gallardo was slated to start on Saturday against the Rays in Port Charlotte, Fla., but the game was canceled due to rain in the top of the first inning.
• In other pitching news, right-handers Brad Brach, Darren O'Day and Tyler Wilson each pitched two innings in a Minor League intrasquad game on Sunday, while Mychal Givens went one inning. After Monday's off-day, Mike Wright will start on Tuesday against the Twins and Miguel Gonzalez on Wednesday against the Pirates.