Frasor made his second rehab start for Class A Advanced Dunedin on Saturday, throwing a clean inning and striking out a pair.
"Very good," manager John Farrell said when asked how Frasor felt. "[He's] available [on Monday] at the earliest."
The right-hander threw two innings with Dunedin during his rehab assignment. He didn't allow a hit or walk and struck out four batters.
Frasor, who hasn't pitched since a July 16 outing against the Yankees, had been feeling discomfort in his throwing arm for a while leading up to his stint on the disabled list.
The veteran has appeared in 42 games with the Blue Jays this season, and sports a 4.00 ERA with 13 holds and a career-high 11.25 strikeouts per nine innings.
Frasor, who has spent all but 20 games of his nine-year career with the Blue Jays, is set to become a free agent at season's end.