The Japanese right-hander was scratched from his scheduled start against Washington on Sunday and is expected to be replaced by rookie Dave Hernandez, who will be recalled from Triple-A Norfolk. To make room for Hernandez, Baltimore will place Uehara on the DL.
"I would say that's a likelihood that would happen," Orioles manager Dave Trembley said Saturday.
Uehara, 34, was on the disabled list from May 27 to June 10 with a strained left hamstring. In his third start since his return, on Tuesday night against the Florida Marlins, he left after throwing 76 pitches.
Uehara, the first Japanese-born player in Orioles history, is 2-4 with a 4.05 ERA. He is winless since April 13 and has pitched seven innings only once.
Trembley believes Uehara can be a productive starter with Baltimore -- but only if he's healthy.
"I talked to Koji today. This guy, he feels like he's let me down, he feels like he's let us down," Trembley said. "I had to tell him that's not the case. There's a lot of baseball to be played, there's the whole second half of the season to be played.
"What we want to do is get him 100 percent healthy and then get him out there to pitch."
While the Orioles were preparing to put Uehara on the DL, they signed top draft pick Matt Hobgood, putting pen to paper in an informal ceremony before Baltimore faced the Nationals.
"We have a deal!" exclaimed scouting director Joe Jordan before engaging in a hearty handshake with the 18-year-old, who gets a signing bonus of $2,422,000.
Hobgood, a high school pitcher from California, was the fifth overall pick in baseball's amateur draft on June 9. The 6-foot-4 right-hander has a fastball that has been clocked at 95 mph and a very good curveball.
"It's going to be a great addition to a system that is improving, talent-wise," Jordan said.
Upon signing, Hobgood flashed a wide smile that showed his braces.
"Sweet!" he said. "This is where I wanted to go. I couldn't be happier."
Hobgood got to know Baltimore during a trip to the city before the draft and got reacquainted this weekend, visiting the Inner Harbor and Camden Yards with his family.
The 245-pound Hobgood went 9-0 with a 0.38 ERA during his senior season at Norco High. He was named the 2008-09 Gatorade national baseball player of the year.