While we Mets fans continue to bask in the afterglow of obtaining Johan Santana, it should be noted that acquiring the ace — while extremely important to the Mets’ hopes — is not necessarily the key to winning the NL pennant (or the NL East, for that matter).

Rather, it could be argued that the key individual to the Mets’ 2008 success is Carlos Delgado.

Of course, we’re making huge assumptions while suggesting this proclamation. For example, we’re assuming that Jose Reyes and David Wright continue to develop their overall games, or at least perform similar to their 2007 levels. And we’re assuming that the Mets bullpen will rebound from their disastrous performance in the last two months of the ’07 season. And we’re assuming that John Maine and Oliver Perez are at least as good as their respective first halves of 2007.

Yes — if the Mets are to succeed, Santana, Wright, Reyes, Maine, Perez, and the bullpen must deliver to certain expectations. If any of them falter, things are going to be tough. Assuming they all do what we expect them to, then the next big “if” falls on the broad shoulders of Delgado.

When the Mets obtained Delgado in the winter following the 2005 season, they expected to be getting a bonafide middle-of-the-order slugger who would strike fear into the hearts of opposing pitchers and provide protection to vulnerably dependent Carlos Beltran. In his initial season as a Met, Delgado delivered — and so did the rest of the offense. The 2006 Mets were an offensive juggernaut, and one of the keys to their running away with the NL East.

On the one hand, I strongly agree with the theory that “good pitching beats good hitting”, and believe that any championship team requires strong pitching above all else. However, take a look at the 2006 Mets — they had only two pitchers with more than 10 wins, no starter with 200 IP, no legitimate “ace”, and only one pitcher with at least 20 starts and an ERA under 4 (Tom Glavine, and barely at 3.82). Yet, despite their lack of dominance on the mound, the Mets were a runaway winner that year — partially because the relief corps was unbelievably good and mostly because their offense made up for the shortcomings.

Many point to Jose Reyes as the ignition for the offense — and that’s true. However, for the Mets offense to take over games, they need the meat of the order to deliver. And Carlos Delgado is the mailman.

When Delgado is hitting, Beltran is relaxed. When Beltran is relaxed, he is patient, selective, and hits at the levels befitting an individual earning $18.5M per year. When Beltran’s hitting, Reyes is scoring — as is Luis Castillo and David Wright. On the other hand, when Delgado is not hitting, Beltran presses, tries to do too much, and fails. We saw how badly he could fail in 2005, and while 2007 wasn’t a bad year, it didn’t quite meet our expectations. 33 HRs and 112 RBI are good numbers from a guy hitting third or fourth, but we know Beltran can do better. He’s paid to do better. Those are great numbers for a #4 hitter in 1985, but run of the mill for a 21st century cleanup hitter. More specifically, we know Beltran can be more consistent; his 2007 was marked by hot and cold streaks — with the hot ones being unconscious and helping to pad the final stats. Part of the inconsistency was due to nagging injuries, to be sure. But part of it also was due to Delgado’s struggles.

In fact, Delgado didn’t just struggle — he disappeared for long stretches at a time. When Moises Alou (speaking of disappearances) was present, Delgado’s troubles weren’t as noticeable, but with Alou gone — wow, was the emptiness glaring. Suddenly, it was imperative that Beltran produce, that Shawn Green make a contribution, that Paul LoDuca continue to hit like he did in 2006, that anyone playing second base add something to the offense. Further, Jose Reyes’ power reduction (compared to ’06) was noticeable, and it shouldn’t have been. Thank goodness for Wright, or the Mets might have finished in third place instead of second.

Right now, the Mets lineup starts off like this: 1. Reyes, 2. Castillo, 3. Wright, 4. Beltran. After that, everything is up in the air. We hope that Delgado fills #5, and that Alou remains healthy to handle #6, because 7 and 8 are Ryan Church and Brian Schneider. Oh boy, there’s another reason Delgado has to hit — the lineup is suddenly only seven deep, harking back to the days of Rey Ordonez floundering in the eight hole. Add in the foregone conclusion that the oft-injured, 41-year-old Alou will be lucky to play in 100 games, and the pressure on Delgado compounds. Believe me, I love Endy Chavez and Marlon Anderson as much as the next guy, but if they are in the lineup as often as we think they might be, Delgado HAS TO be slugging again. This .258 / 24 / 87 nonsense is not going to play well. It’s not so much the numbers as the approach by opposing pitchers, and the overall “feel” or mentality of the rest of the lineup. The threat of the longball has to return — opposing hurlers have to be worried about serving up homers. If not, Delgado becomes a non-entity, an easy out — and there are no worries if the people ahead of him are put on base. Heck, it’s a nice strategy to set up a double play.

Adding to the discomfort of the situation is the fact that there is no backup plan in the event Delgado falters again. Since the Mets completely emptied the farm of any close-to-MLB-ready talent this winter, there’s no help within the organization (which is why I still advocate the pickup of a Nelson Cruz-type, but that’s for another day). If Delgado fails in the five spot, and Alou is as (un)available as we expect, then either Ryan Church needs to turn into Travis Hafner or the Mets are in big trouble. Besides not having an heir apparent, there’s little to deal away for a veteran bat at the trade deadline. Ironically, Mike Piazza — if he remains unsigned — would look like a viable possibility (though it will never happen).

Don’t misconstrue my message — I don’t believe the Mets need to slug their way into the postseason the way the Phillies did last year. But the offense definitely needs to improve over their 2007 output. Reyes returning to 2006 form will help, absolutely, but a renaissance by Delgado is just as, if not more, vital. In this day and age of offense-dominated baseball, the Mets can’t win with a lineup that crumbles after the cleanup spot. Remember, Johan only helps once every five days — and he can’t be expected to throw a three-hit shutout every time out.