Johnson joined Toronto in an offseason blockbuster trade with Miami. He is to start Tuesday night against the Giants in San Francisco.
He has missed the last six weeks with a right triceps injury. In four starts, Johnson is 0-1 with a 6.86 ERA.
Davis is recovering from a strained left side and hasn't played since May 10. In 26 games, he has a .284 average with one homer, four RBIs and eight stolen bases.
Also, 40-year-old right-hander Ramon Ortiz went on the 15-day DL. He left Sunday's game in tears in San Diego after straining his right elbow. He was to have an MRI Tuesday. He is 1-2 with a 6.04 ERA.