The New York Mets plan to promote left-handed prospect Steven Matz and will use some form of a six-man starting rotation, according to a source.

Matz, 24, was informed of the impending promotion Thursday.

New York plans for Matz to debut on Sunday against the Cincinnati Reds at Citi Field.

He has a 7-4 record and 2.19 ERA and has struck out 90 batters in 90 1/3 innings with Triple-A Las Vegas this season.

Moving to a six-man rotation once again would allow the Mets to limit the innings of their young starters.