A 35-year-old right-hander, Jackson would be appearing in his 17th big league season. He signed a minor league contract with Oakland last month and was 1-0 with a 6.75 ERA in three games, two at Triple-A and one at Class A. He is expected to report to the Blue Jays and start at San Francisco on Wednesday.
"Hopefully he's going to give us a spark,'' Blue Jays manager Charlie Montoyo said. "We need an arm like that and he's been around. I've seen him for a long time now so I'm hoping he helps us out.''
Toronto has four starting pitchers on the injured list, including right-handers Clay Buchholz (shoulder) and Matt Shoemaker (out for the season after knee surgery) and left-handers Ryan Borucki (elbow) and Clayton Richard (right knee).
Jackson has gone 104-123 with a 4.60 ERA in 394 games. He made his big league debut with the Los Angeles Dodgers in 2003 and also pitched for Tampa Bay, Detroit, the Chicago White Sox, Arizona, St. Louis, Washington, the Chicago Cubs, Atlanta, San Diego, Miami, Baltimore and Oakland. He was 6-3 with a 3.33 ERA in 17 starts for the Athletics last season, when he tied Octavio Dotel's record of 13 teams.
Montoyo said Jackson was preferred to Triple-A alternatives because Toronto's pitching prospects are not performing.
"The kids that are at Triple-A are struggling a little bit now so we want to give them more time for them to get better,'' Montoyo said. "You don't want to bring anybody up to the big leagues when they're struggling in the minor leagues. Edwin Jackson is a perfect fit right now.''