Cashen, 88, passed away this past Monday.
He was the general manager of the Mets from 1980 to 1990, and also served as interim GM for a brief stint in 1998. He was responsible for putting together the 1986 World Series champions.
The patch will be displayed on the right sleeve of the team's uniform below the Ralph Kiner patch. It will be worn on all jerseys for the remainder of the year starting this Friday at Citi Field. Also, prior to Friday’s game, the Mets will hold a moment of silence in Cashen's memory.