"He's started playing catch, feeling better," general manager Alex Anthopoulos said. "We're hopeful to get him into a rehab game starting on the 21st. That's not set in stone, but that's kind of the date that we've had."
The timing of Johnson's potential return appears later than originally anticipated. Toronto's No. 4 starter would have been eligible to come off the 15-day disabled list on May 13, and there was some hope that he would be able to return to the big leagues on May 21 when the club needs another starter.
That has now been ruled out, and the Blue Jays will need to search for an alternative either through a trade or in the Minor Leagues. Toronto doesn't need a fifth starter until May 21 because of a pair of off-days next week.
Johnson is 0-1 with a 6.86 ERA in four starts this season. He is eligible for free agency at the end of the year.
Gregor Chisholm is a reporter for MLB.com. Read his blog, North of the Border, and follow him on Twitter @gregorMLB. This story was not subject to the approval of Major League Baseball or its clubs.