Well, at least now Red Sox sufferers know.

Manny Ramirez’ season-long impersonation of Tom Brunansky remains a mystery, but now we have a built-in excuse whenever David Ortiz bounces out feebly to second base with runners at the corners in the bottom of the eighth.

He’s playing hurt, which of course is the noblest thing you’ll see on the tube this summer aside from Pam Anderson jiggling her way into the water to save that poor guy in the DirecTV commercial.

Buy Big Papi a beer and thank him for making the supreme sacrifice so we can all spend the rest of our summer laughing at the Yankees.

Please! I don’t want to hear it. This is baseball. It’s a 162-game season. Everybody’s dragging around an extra 25 pounds of muscle compared to 1986 for whatever reason you choose to believe. Everybody’s playing on over-stressed knees and ankles that hurt like hell.

Some simply do it better than others, and watching Ortiz unravel into a punch-and-Judy shadow of his giant self has been, well, painful.

Ortiz has cranked out 14 home runs and 54 RBIs. Nice midseason numbers by Bob Horner standards, I suppose, but not what we’ve rightfully come to expect from Boston’s most bodacious clutch hitter in my lifetime.

He ejected Mr. Rawlings from the park 51 times last season. Roughly half those homers came after Ortiz believes he sustained a torn meniscus in his right knee during batting practice at Yankee Stadium in early June.

You got it. Last June. Thirteen months ago. Thirteen months in which Ortiz could have sought second, third and ninth opinions to tell him that rest and/or surgery are the only fix.

Let’s not forget that the Sox spent last August and September in a fold that would be legendary if we weren’t still delirious from 2004, sinking from the American League East lead to the indignity of third place. The truly heroic decision would have been for Ortiz to consider the obscene supply of Benjamins the franchise has committed to him and shut it down, way back then.

Instead, probably on the advice of the Sox’ own conflicted doctors, he played on. It’s a stubborn streak that carried right through winter, spring training and stealing Kevin Youkilis’ spot on the All-Star team.

To the seasoned Red Sox fan, Papi’s slide is all too eerily reminiscent of Jim Rice’s freefall from MVP candidate in 1986 to nearsighted dude wielding a toothpick at the plate in ’87.

Ortiz is having a good, not great, season for a well-balanced team that could survive four to six weeks without him. For the greater good, he needs to get that knee scoped and find out if the damage is reversible.