Patton left the team over the weekend to attend a hearing yesterday in Houston related to his DWI arrest over the winter.
To make room for Patton, the Orioles once again have designated left-hander Mark Hendrickson for assignment.
Hendrickson appeared in one game after replacing Patton, allowing one run and two hits in one inning against the Yankees in Game 2 of Sunday's doubleheader at Camden Yards. He's 1-0 with a 5.73 ERA in eight games and 11 innings with the Orioles this season.
It's believed that Hendrickson, 37, has agreed to accept another outright assignment to Triple-A Norfolk if he clears waivers. He had to sign a consent form, just as he did earlier this summer.
Patton, 25, is 0-1 with a 3.86 ERA in 11 appearances and 16 1/3 innings with the Orioles this season.