Eldred broke a thumb last year while playing in the minor leagues.
"The biggest thing for me is I'm healthy," Eldred said. "When you have a hand injury, you worry that you might lose power, but I am feeling as strong as I ever have."
Zach Duke, who may start the Pirates' opener, allowed two runs and two hits in three innings. He struck out three and walked none.
"My stuff feels really good for this part of the spring," Duke said. "I pretty much threw my pitches where I wanted to."
Toronto starter Josh Towers allowed one hit in two innings -- Eldred's homer.
"It was the best I have felt in a long time," Towers said. "I felt I had the control over exactly what I wanted to do. The only thing I couldn't do is I really didn't pitch inside to righties too well."
Eddie Garabito hit a two-run homer for the Pirates, and Vernon Wells homered for Toronto.
Pittsburgh is 0-4 despite holding a lead in all five games.
Blue Jays reliever Brandon League (lateral muscle strain) threw off the mound for the first time Monday and reported no problems. "I'll throw two sides and a BP before getting into a game in about a week," he said. ... LHP Jo Matumoto is scheduled to pitch in a "B" against the Philadelphia Phillies on Thursday.
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Barria scheduled to start for Los Angeles against Houston
Houston Astros (88-61, first in the AL West) vs. Los Angeles Angels (72-77, fourth in the AL West)
Ray scheduled to start for Blue Jays at Rays
Toronto Blue Jays (84-65, third in the AL East) vs. Tampa Bay Rays (92-58, first in the AL East)
Manning expected to start as Tigers host the White Sox
Chicago White Sox (85-64, first in the AL Central) vs. Detroit Tigers (72-78, third in the AL Central)
Alexy scheduled to start for Texas against New York
Texas Rangers (55-94, fifth in the AL West) vs. New York Yankees (83-67, fourth in the AL East)