Multiple outlets, including MLB.com, reported earlier in the week that the deal was imminent, and the Sun on Thursday reported that the contract -- which includes a $2 million pickup option for 2010, vs. a $500,000 team buyout -- is done, pending a physical that will most likely take place on Tuesday.
Orioles president Andy MacPhail's words to the Sun indicate that Zaun, who will turn 38 in April, will be the likely starter on Opening Day.
"We expect him to do a lion's share of the catching, and we'll see how the season progresses," MacPhail told the paper.
For Zaun, who hit .237 with six home runs and 30 RBIs in 86 games last year for the Toronto Blue Jays, it's a return to the team that drafted him in 1989. Zaun played for the Orioles in 1995 and was traded to the Florida Marlins the following year.
Zaun also has a familial tie to the team as the nephew of another Orioles catcher, Rick Dempsey, who now works for MASN as a broadcaster.
"[Zaun's] a veteran guy with some history here, and he's got a good reputation for handling a pitching staff," MacPhail told the Sun.
Doug Miller is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.