The end of the road remains ironclad. But the path there has grown treacherous.

The Mets bullpen’s journey to closer Edwin Diaz — and the near certainty, these days, of a soon-to-be secured win — has been filled with nightly uncertainty.

Take Tuesday night’s 4-2 loss to the Yankees. Joely Rodriguez was brought in for the seventh inning in a 2-2 game. He promptly gave up a run on three hits, exiting while leaving inherited runners for Adam Ottavino, who allowed one more to score for an ultimately insurmountable deficit.

Rodriguez’s repeated meltdowns have become notable. The 30-year-old, who owns a 5.11 ERA and -0.4 WAR in 42 appearances this season, is the only lefty in the bullpen, a unit general manager Billy Eppler and the Mets opted not to significantly reinforce at the trade deadline.