CINCINNATI -- The possibility exists that the Mets could go to a six-man starting rotation at some point in the final two months of the season.

Manager Terry Collins said the health of Johan Santana and Chris Young plus the development of Matt Harvey are all factors in any decision yet to be made.

“There are a lot of variables to putting an extra guy in there,” said Collins.

Harvey, the 2010 first-round draft choice, is 1-3 with a 3.63 ERA and a .205 batting average against him in 22-1/3 innings in his four starts since being called up from Triple-A Buffalo on July 24. He was 7-5 with a 3.68 ERA in 110 innings at Buffalo this year with 110 strikeouts compared to 48 walks allowed.

Both Collins and Harvey said neither of them has been informed of any sort of innings pitched restriction from general manager Sandy Alderson or any other club management a la Steven Strasburg of Washington.

Harvey is scheduled to start Thursday in the finale of the three-game series against the Reds.

“All I’m doing is trying to prepare for each start and go as long as I can in each start,” said Harvey. “I obviously would like to turn my record around and help the team get some more wins but getting called up, being here and learning from all of these guys has been an awesome experience.”

Young is starting the opener of the series tonight, while R.A. Dickey is scheduled to start on Wednesday. Santana, who was roughed up to the tune of eight runs in 1 1/3 innings in his last start against Atlanta, is set to pitch the opener of the three-game weekend series at Washington on Friday.
Santana threw on Sunday and reported no health issues, said Collins.

“The biggest argument against it is that you don’t get guys out there on a consistent enough basis,” said Collins. “You don’t know how that’s going to affect some guys.”