To make room for Verrett, the Mets will place RHP Bobby Parnell on the 15-day disabled list with right shoulder tendinitis, the team said.
According to Rubin, Parnell has had no major setback but is dealing with arm fatigue after returning from Tommy John surgery.
However, a source told Mike Puma of the New York Post that Parnell had the choice to either go to the DL or get designated for assignment (Aug. 18).
Parnell will earn $3.7 million this season, after which he is eligible to be a free agent.
Since July 23, Parnell has a 14.14 ERA, allowing nine runs over 10 outings. For the season, Parnell has a 5.59 ERA in 19 1/3 innings.
In six outings with the Mets this year, Verrett has allowed just one run in 12 1/3 innings.