Glasnow (elbow) is slated to begin a rehab assignment with Triple-A Durham on Wednesday, Marc Topkin of the Tampa Bay Times reports.
Glasnow will throw a bullpen session sometime before joining Durham. Once he begins the assignment, the Rays will build him up slowly and have already determined he will throw just one inning in his first rehab game. The right-hander has not yet been ruled out for a late-season return in a relief role.