The game never started and was finally called after a delay of nearly two hours.
Saturday's doubleheader will start at 5:05 p.m.
The Twins began the day in second place in the AL Central, one game behind the Chicago White Sox. Minnesota trailed Boston by 5½ games in the wild-card race.
The weary Twins came to town after playing their 16th extra-inning game of the season, a 3-2 loss to Kansas City at home Thursday. But it wasn't exactly a day of rest for Minnesota, which had to spend more than five hours at Camden Yards waiting for the rain to subside.
The rainout could have a negative influence on the Minnesota rotation, but manager Ron Gardenhire said Friday afternoon he would try to keep his pitchers working on a regular schedule.
"We're going to stay with what we've got," he said. "Not hurt anybody in the process, but try to win games."
The scheduled starters for Friday's game will go in the opener: Minnesota's Scott Baker against Daniel Cabrera. Glen Perkins will pitch for the Twins in the nightcap against Garrett Olson.
Baltimore came in with 10 losses in its last 12 games. The Orioles haven't won a series since taking two of three in Detroit on Aug. 15-17.
But manager Dave Trembley promised the Orioles would give an honest effort against the Twins.
"I think there is an obligation when you are playing contending teams to bring your game up to that level and play with some energy -- and spirit," he said Friday afternoon. "I think that's why these guys are who they are -- they like to compete."