Johnson will now pitch the series finale Sunday against the Rangers. The right-hander pitched five innings against Texas at home on Sunday, when he had a blister on his right middle finger.
R.A. Dickey will move up a day to start in Johnson's spot Saturday. The knuckleballer will still be pitching on normal rest.
The change was announced before the four-game series opener in Texas on Thursday night.
The Blue Jays had initially pushed all their starters back a day after their game Wednesday night at the Chicago White Sox was postponed because of the forecast for storms.
Dickey pitched Monday night against the White Sox.