Trumbo hit a two-run homer and Schoop's was a solo shot off Pittsburgh starter Jonathon Niese. Hardy connected off Jorge Rondon.
It was Trumbo's fourth home run, Schoop's third and Hardy's first.
Niese worked six innings, allowing four runs on six hits.
''I care. I'm still preparing. Today was just get to that 100-pitch mark. I felt I was pretty efficient. Made a couple mistakes that during the season, when I go over hitters before the game, I probably don't make those mistakes. I can't say never, but more than likely won't,'' Niese said.
Tyler Wilson, who will begin the season in the rotation if Kevin Gausman starts out on the disabled list, allowed Matt Joyce's home run in the first. He gave up the run on two hits in three innings.
Baltimore relievers Zach Britton and Darren O'Day worked on consecutive days for the first time this season. Britton pitched a scoreless seventh, O'Day allowed three runs in the eighth.
Joey Rickard's ninth-inning RBI single won the game.
Pirates: It was just the third official Grapefruit League start for Niese and hadn't pitched since March 8.
Orioles: Wilson took some positives from his start.
''Those are the types of experiences that spring training is for. If you go smooth sailing through 15 innings in spring training, and then all of a sudden the first inning on Opening Day, you've got men on first and second with nobody out, how do you manage the game? That's the ultimate goal in pitching is how do you get outs? How do you manage the damage in a situation?'' Wilson said.
Pirates: INF/OF Michael Morse left the game in the fourth inning with an injury to his right leg.
''I felt a little grab while running,'' Morse said. ''It's nothing big. It's one of those spring training things where they take you out to play it safe.''
Orioles: C Matt Wieters, who hasn't caught since leaving a game on March 12, was the designated hitter. He was 0 for 4.
Wieters was scheduled to throw from 120 feet to test his sore right elbow.
LHP Brian Matusz, who's sidelined with a lower back strain, has the flu.
RHP Chaz Roe left the club for a few days because his wife is scheduled to deliver a child.
Pirates: RHP Ryan Vogelsong starts against the Boston Red Sox in Fort Myers on Friday night. LHP David Price is the Red Sox starter.
Orioles: RHP Chris Tillman starts against New York Yankees RHP Ivan Nova in Sarasota on Friday.
OLMOS REACQUIRED: Baltimore acquired minor league LHP Edgar Olmos from the Chicago Cubs for a player to be named later.
CUT: Pittsburgh reassigned RHPs Wilfredo Boscan and Guido Knudson to minor league camp.