It seems pretty obvious that the biggest question mark about the Pirates’ ability to stay in the thick of the NL Central race concerns the bullpen’s ability to keep up its stunning contributions.

The irony is that it isn’t really a bullpen question, but a rotation question. Unless starters begin taking some burden off the relievers, they’re going to run out of gas long before the schedule runs out of games  — pretty much like last season, when this trend had a lot to do with Collapse II.

Through Monday’s games, the Pittsburgh bullpen has worked the most innings (209) in the NL. But that’s only the big picture, and the insets are more troubling: Pirates relievers have worked 65 more innings than the Cardinals, and 45 more than the Reds. The long-range effect on the division race of that disparity should be obvious.

The Bucs have already done a bit of shuffling to keep fresh arms in the bullpen, but those are bandages, not cures.

Complete games from starters? Forget that; the Bucs don’t have any, but that doesn’t make them unique in today’s game. But how about the fact they haven’t even gotten a single eight-inning start?

Runaway pitch counts aren’t the problem. Somewhat surprisingly, perhaps, I think a bigger issue is manager Clint Hurdle having fallen in love with the Melancon-Grilli end-game. Hurdle can’t be blamed for depending on the duo, which has been flawless.

But he has to ease up on the starters’ leash. Numerous times they have been removed when comfortably under 100 pitches after seven.

In a twisted sense, the offense could also help. The Bucs have played nothing but tight games, so fresher arms at the end are desirable. More comfortable leads would convince Hurdle to let starters work longer and let relievers catch their breaths.