Matzek has struggled with his control early in the season, particularly in his last start against Arizona on Wednesday, when he pitched two innings and gave up four runs, three hits and six walks. Manager Walt Weiss said the Rockies were still considering their options for a replacement for Matzek in the rotation.
Rosario played in 10 games for the Rockies before being optioned two weeks ago to Albuquerque, where he hit .343 with four doubles and four RBIs in nine games.
Rosario has three doubles and a home run in 14 at-bats with the Rockies this season.
Matzek is 2-1 with a 5.96 ERA in five starts for the Rockies this season, his second in the big leagues. He is 8-12 with a 4.06 ERA in 24 career starts.