We might remember Labor Day as the new beginning and the real end for two of the game’s greatest all-time pitchers.

Pedro Martinez, relying more than ever on high pitching IQ rather than high heat, navigated five winning innings against the woeful Reds. It was a positive first step in a return from shoulder surgery. Let’s see how he feels today, let’s see if he can keep going out every five days from now until the end of the Mets’ playoff run.

But this was encouraging, certainly more encouragement than the Yankees are experiencing with Roger Clemens.

The Rocket was forced from his start against the Mariners after four innings with an elbow injury. He was sent for an MRI. Joe Torre said it was almost certain Clemens would miss at least one start. But Clemens is 45 and maybe – finally – we have seen what will take him out of the game.

Here is something to think about: Clemens has built a Hall-of-Fame career on machismo. He envisions himself as the pitching John Wayne. But you have to wonder if that mentality helped cost the Yankees two games this season when it does not appear they have two games to give away.

He purposely hit Toronto’s Alex Rios on Aug. 7 and got a suspension that cost him a game. Jeff Karstens started in Clemens’ place against the Orioles and the Yankees were bombed 12-0.

Before his last start, Clemens had reported elbow problems, but repeatedly promised the Yankees he was fine. Just he was not fine. He never looked right on the mound against the Mariners.

Now we will never know if the Yankees would have won the game Karstens started if Clemens had started instead or if Clemens had stepped aside on Labor Day to have Mike Mussina start. Maybe Felix Hernandez was dominating the Yankees no matter the identity of the opposing starter.

But it at least makes me wonder.