Even I’m pulling the plug.

As recently as a week ago, I was defending the Arizona Diamondbacks’ chances in the NL wild-card race. In a pool lousy with flawed teams, the Diamondbacks’ young position-player talent stood out, as did their having the best starting pitcher, Brandon Webb, in the group. They’d made the in-season transition to Stephen Drew and Carlos Quentin and even added an innings guy to the rotation in Livan Hernandez. I’d written back in March that this could be a much better team in the second half than it had been in the first, and that seemed to be happening.

Two weeks ago, the D’backs lost a series of close games to the Padres, Giants and Dodgers that cost them ground in both the NL West and wild-card standings. In the aftermath, I still considered them a contender because of a schedule and the aforementioned talent shift. Even after they lost two of three to the Padres last week, I wasn’t convinced that they were done.

They’re done now.

The Diamondbacks’ weekend in Washington was as devastating a series as I can remember a team having. What looked like an opportunity to gain ground on the wild-card leaders turned into a death march into the offseason. The Diamondbacks led all three games going into the bottom of the eighth inning, and lost all three. They were up 6-1 after 7 ½ innings in the first game of a day-night doubleheader Saturday before Tony Pena and Jorge Julio allowed five runs in the next two innings. They lost 7-6 in 11 innings. In the nightcap, Livan Hernandez turned a 3-1 lead into a 4-3 loss in a span of 11 pitches, two of which were hit out of the park by Ryan Zimmerman and Austin Kearns. Finally, on Sunday, Brandon Webb gave up four hits in a four-run eighth inning, pushing the D’backs to a 5-3 loss.

When a team loses a series of games like this, there are usually specific decisions that can be criticized. I’m not sure that’s the case here. Certainly, Bob Melvin seemed to shy away from using his bullpen after the first game, but neither Hernandez nor Webb was into a dangerous pitch-count area when they blew their leads. The only point at which I think Melvin might have made a change was in the eighth inning yesterday, when he allowed a tiring Webb to face Kearns with the bases loaded in a tie game. At that point, Webb got ahead 0-2 on Kearns before eventually surrendering the tie-breaking double. It’s not clear to me that a choice between Webb and one of the Diamondbacks’ right-handed relievers at that point has a right answer.

Despite periodic runs by Julio, by Pena, by Jose Valverde, the Diamondbacks bullpen was never a strength. The pitchers doing the best work never seemed to be getting the highest-leverage innings. That’s not a criticism of Melvin; I think he tried to get his best pitchers into the right roles, but the definition of “best pitchers” changed frequently enough to turn the whole exercise into a guessing game. For instance, Julio and Pena pitched well enough in the period right after the All-Star break to become Melvin’s late-inning guys. They then had ERAs of 5.06 and 6.59 in August. Meanwhile, Valverde and Luis Vizcaino, who’d fallen out of favor with poor work earlier in the year, were pitching their best baseball of the year in the sixth inning of 5-1 losses.

There are a lot of live arms on this team, although command is a problem for almost all of them. Assembling a good bullpen in 2007 may be more a matter of selection and coaching than spending money on outside help. A good left-hander-the Diamondbacks have 13 innings of left-handed relief all season-is essential, preferably one used outside of a specialist role.

It would have been nice to see the Diamondbacks playing their best players all the time. The team has been cutting into Stephen Drew‘s playing time since Craig Counsell came off of the DL, splitting the starts at shortstop between the young player with the 850 OPS and the utility-infielder-Peter-Principled-into-starting-jobs batting .095 since his return. Eric Byrnes was playing over Carlos Quentin despite a .295 OBP since the All-Star break, and similar situations were in place behind the plate and at first base, where productive young players were sharing jobs with veterans who had superficially impressive stats but who were being outplayed by their competition down the stretch.

With the 2006 season essentially over, Melvin’s charge should be clear: get the 2007 Diamondbacks on the field as often as possible. That means Chris Young, that means Conor Jackson, that means Chris Snyder. There could be a place for veterans like Byrnes and Luis Gonzalez–actually, that would be a hell of a left-field platoon-but that’s for Josh Byrnes to work out with agents. Melvin’s job is to let his good young players get reps in the major leagues in preparation for one heck of a battle with the Dodgers in 2007.

If the weekend in Washington didn’t make their status clear, the Diamondbacks lost another heartbreaker today, scoring four runs in the top of the first and taking a 5-0 lead over the Marlins, only to allow six runs in the sixth on the way to an 8-5 loss. They’ve now blown leads of at least two runs in each of their last four games, and have joined the Rockies and Brewers as the teams who have fallen out of the NL wild-card race. But like those teams, the Diamondbacks have enough young talent to soften the blow and make “next year” a rallying cry, not sour grapes.

So if not the Diamondbacks, who will win the NL wild card? We’ll check back on that later this week.