The Rockies announced Monday that Collins has elected to opt out of the 2020 season.
Collins will be a part of the Rockies' 60-man summer camp.
Collins signed a minor-league contract with the Rockies on Wednesday.
Collins was outrighted to Triple-A Iowa on Saturday, Mark Gonzales of the Chicago Tribune reports.
Collins was designated for assignment by the Cubs on Friday, Mark Gonzales of the Chicago Tribune reports.
Collins was optioned to Triple-A Iowa on Friday, Jesse Rogers of ESPN.com reports.
Collins had his contract selected from Triple-A Iowa on Tuesday, Mark Gonzales of the Chicago Tribune reports.
Collins was optioned to Triple-A Iowa Monday.
Collins was recalled from Triple-A Iowa on Saturday.
The Cubs optioned Collins to Triple-A Iowa on Thursday, Bruce Levine of 670TheScore.com reports.