• O's Hot Stove Tracker
"Darren is one of those guys that, he wants to return the commitment that we make to him," manager Buck Showalter said at Orioles FanFest on Saturday. "He wants to be a really good pitcher for the Orioles for the next four years -- and maybe beyond that. He'd like to finish here. He got a great contract and deserved it."
O'Day, 33, was named to the American League All-Star team in 2015 and went 6-2 with a 1.52 ERA in 68 games.
The right-hander is 23-8 with a 1.92 ERA since joining the O's in 2012.
To make room on the 40-man roster, infielder Rey Navarro was designated for assignment.
William Boor is a reporter for MLB.com. Follow him on Twitter at @wboor. This story was not subject to the approval of Major League Baseball or its clubs.