NEW YORK -- Free-agent first baseman Rafael Palmeiro still isn't sure why he tested positive for steroids, he told The New York Times for a story published Wednesday.

The 41-year-old Palmeiro was suspended in August for 10 days by Major League Baseball. His steroid test in May came up positive -- just six weeks after he testified in Congress that he had never taken the performance-enhancing drugs.

"I wish I could pinpoint exactly what happened," Palmeiro said. "I would think it was the B-12. I'm not certain of that; I can't prove it."

He has said former Baltimore Orioles teammate Miguel Tejada gave him vitamin B-12 earlier in the season, and suggested it might have been tainted with performance-enhancing drugs.

"I wish I could have turned in the vial for testing," Palmeiro said. "But when I found out, it was long gone and I couldn't come up with it.

"I'm going to take the responsibility. ..."

Burnitz signs with Orioles

Free agent Jeromy Burnitz and the Orioles have agreed on a two-year contract, pending the results of a physical. A team source said Wednesday the deal will pay the former Cubs outfielder between $10 million and $12 million.

Glaus dealt to Toronto

The Arizona Diamondbacks dealt Troy Glaus and top minor league shortstop prospect Sergio Santos to the Blue Jays on Tuesday for Gold Glove second baseman Orlando Hudson and pitcher Miguel Batista.