Middleton (forearm) threw off the mound again Friday and is set for a rehab assignment next week, John Denton of MLB.com reports.
Middleton is on the cusp of a rehab assignment according to manager Oli Marmol, who explained that the reliever will report to either Double-A Springfield or Triple-A Memphis for his assignment this upcoming week. The right-hander is eligible to return from the 15-day injured list May 17, and he appears to be on track to return from his forearm injury on or close to that date.