Source: Mets set to promote Steven Matz, go to six-man rotation

MILWAUKEE -- 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 ESPN.com.

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.

The Mets have been concerned about rising innings counts for their young pitchers, including Jacob deGrom and Noah Syndergaard. Matt Harvey, returning from Tommy John surgery, is on pace for more than 200 regular-season innings this season -- a plateau the organization wants to avoid reaching.

Team officials initiated a six-man rotation in early June, but quickly abandoned the plan and placed Dillon Gee in the bullpen. Gee subsequently was designated for assignment, and is now pitching for Las Vegas.

Matz's promotion will be a homecoming, too. He grew up a Mets fan in Stony Brook on Long Island. The team selected him in the second round in 2009, during former general manager Omar Minaya's regime.

"The guy has just been mowing through lineups down there," said catcher Johnny Monell, who has split the season between the Mets and Las Vegas.

Matz took a no-hit bid two outs into the seventh inning on April 24 at Reno.

"I think the fastball was mid-90s, but it looks like he's handing you the ball almost. It just explodes out of his hand, onto you," said ex-Met Nick Evans, who plays for Reno. "It's pretty impressive. He definitely throws a good curveball. And he throws his changeup for a strike. ... He's definitely been the best arm we've seen in this league so far this year. The consensus on our team is he's the real deal."