On Tuesday, Pearce connected twice and Jackson once as the Orioles and Toronto Blue Jays played to a 6-6 tie in 10 innings.
Jackson and Pearce are right-handed hitters, play both first base and the outfield, and neither is on the 40-man roster.
They hit back-to-back home runs in a four-run sixth inning against reliever Esmil Rogers. Catcher Luis Exposito hit another.
Five years ago, Jackson hit .300 for the Arizona Diamondbacks. A year later, he was stricken with Valley Fever, and he's struggled to right his career since.
Jackson was 3 for 3 with a single, double and home run. On Sunday, he had two home runs. Jackson is batting .421.
"There's a lot of spring left — a lot of at-bats left," Jackson said.
Jackson is trying to catch manager Buck Showalter's eye.
"Buck is a little-things-in-the-game type of guy. It's not going to be who hits the best," Jackson said.
Pearce's first homer was hit off J.A. Happ, who is trying to make the Blue Jays as either a starter or reliever.
"I thought it went all right. Was glad to get through three innings; felt strong in the first and third. Keep working on getting the pitch count up and everything. Gave up some hits, but they were balls through the infield for the most part. Overall, I feel good about it," Happ said.
Blue Jays manager John Gibbons was pleased with Happ's performance.
"I thought he threw good. Where he's really effective is up. He's opposite of a lot of guys. When the ball stays down they got a few hits there," Gibbons said. "Ball's flying pretty good to left today. But overall I thought it was a good outing for him."
Steve Johnson and Jair Jurrjens are two candidates for the Orioles' fifth starter spot. Both pitched, and not terribly well.
Johnson allowed two runs in two innings and Jurrjens gave up three runs in 2 2-3 innings.
"I felt good physically, so that was good, but obviously the results weren't really what I wanted. I wanted to go out there and pound the zone. Just couldn't really get in a rhythm today, especially early," Johnson said.
Jurrjens, a National League All-Star in 2011, is struggling to regain his form. He signed a minor league contract with the Orioles on Feb. 15. He knows he's one of several who can fill the fifth starter role.
"I'm not trying to think about it. I'm trying to get better and trying to get back to what I used to be. And that's it, that's the only thing I can control. I can't control if the manager decides who is going to win the job. My job is to go out there, try to give the best performance I can and see how it goes," Jurrjens said.
NOTES: The teams combined for 29 hits. ... Andy LaRoche and Ryan Langerhans hit home runs for Toronto. ... Orioles RF Nick Markakis, who was scratched from Sunday's game with neck spasms, said he should be able to play in a few days. ... Blue Jays RHP Dustin McGowan, who's had three shoulder surgeries in the last five years, threw his first bullpen of spring training. ... Baltimore faces Spain's entry in the World Baseball Classic on Wednesday. ... Toronto travels to Lakeland for a game with Detroit. Blue Jays' RHP Brandon Morrow pitches against the Tigers' RHP Justin Verlander. ... Blue Jays RHP Sergio Santos has tenderness in his triceps, and he won't pitch until Saturday.