The Mets released Rosario on Sunday, Will Sammon of The Athletic reports.
Rosario signed a minor-league contract with the Mets on Tuesday, Pat Ragazzo of SI.com reports.
Rosario elected free agency Sunday, Justin Toscano of The Atlanta Journal-Constitution reports.
Rosario cleared waivers Saturday and was sent outright to Triple-A Gwinnett, Grant McAuley of 92.9 The Game Atlanta reports.
Atlanta designated Rosario for assignment Thursday.
Rosario is out of the lineup for Wednesday's game against the Brewers.
Rosario went 0-for-1 with a walk and a stolen base in Wednesday's win over the Brewers.
Rosario is not in the starting lineup for Sunday's series finale against the Mets.
Rosario went 3-for-7 with a walk, two home runs and three RBI across both ends of Saturday's doubleheader split with the Cardinals.
Rosario will start in left field and bat seventh in Sunday's game against the Padres.