The New York Mets plan to promote left-handed prospect Steven Matz from Triple-A Las Vegas and will use some form of a six-man rotation, a source told

Matz, 24, was informed of the impending promotion Thursday. The Mets plan for him to make his major league debut 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. Pacific Coast League batters are hitting .213 against him.

Manager Terry Collins declined to confirm the promotion but said after the Mets' 2-0 win against the Milwaukee Brewers that a rotation announcement would be made Friday in New York.