Given some of the open casting calls the Mets have run over the years, the fact that they’re going into spring training this year with their roster pretty much set should be a relief for all fans.

There will be no auditions in the starting rotation, no mystery as to who will take the important roles in the bullpen, no question about who’s going to play in the outfield. The team has retained a certain amount of flexibility in certain spots – it’s easy to imagine either Xavier Nady or Victor Diaz staking a claim as the main right fielder based on his performance in Port St. Lucie, and the bullpen has a bit of fluidity to it – but for the most part, the Mets’ 25-man roster is set.

The big exception, of course, is at second base, where options range from the bleak to the apocalyptic. Incumbent Kazuo Matsui is, judging by his quasi-Knobaluchian performance the last two years, not suited for a spot on a contending team. Thirty-seven-year-old Bret Boone, last seen hitting .173 for the Minnesota Twins, is a much worse ballplayer. Twenty-two-year-old prospect Anderson Hernandez is best described as Jose Reyes without the speed or power, and hence without the star potential. That leaves 25-year-old Jeff Keppinger as the Mets’ best hope, and the player fans should be most closely keeping an eye on this spring.

Keppinger would probably have had a clear shot at the job last summer if he hadn’t fractured his kneecap; he hit .337 in Triple-A last year and has little left to prove in the minors. He is what he is – a pure hitter who walks very rarely and strikes out even less, hits for very high batting averages (he’s hit .314 in his minor league career), with no power, and plays solid enough defense. The best bet is that he’ll hit .280 BA/.330 OBA/.370 SLG for the Mets this year, which is about what he hit in 124 major league atbats two years ago. There’s almost no chance he’ll hit much better than that, and he probably won’t hit much worse. Given the alternatives, fans should be crossing their fingers that Keppinger shows enough to earn the job going into April, as all his competitors have excellent chances of hitting much worse.

The other main positional competition will be for the fourth outfielder’s role. Here again, Mets fans who want their team to win have a clear rooting interest. While new imports Tike Redman (career .312 OBA) and Endy Chavez (.299) are doubtless good hands at hearts and kind to their house pets, that’s about the best you can say about them. Neither would kill a team as a 25th man – they can handle center field, slap some singles, and steal some bases – but any team with Cliff Floyd and an ongoing mystery in right field can use an outfielder who actually has a chance of being good on the bench.

The Mets’ man should be Angel Pagan, who may prove not to be any better than Redman or Chavez, but has shown enough in the minors to make one think he may be. He’s also, by reputation, a truly superb defender. Here, as at second and as almost always, the Mets would be wise to take a slight risk on a player with a bit of potential rather than turning to a known quantity who’s known not to be any good at all.

On the pitching side, things look more or less set, with the wild card being Cuban pitcher Alay Soler, supposedly much-loved by management and considered a candidate for either the rotation or an important bullpen role, but a mystery to most of us, as he has yet to pitch in America. Could he seize a slot and force Aaron Heilman or Victor Zambrano into the bullpen? It’s unlikely, but possible. That aside, the pitchers to keep an eye on are John Maine and Brian Bannister, indistinguishable 25-year-old control artists with upsides as no.4 starters. Bannister had a fine season last year, running up a 142/40 K/BB ratio in 154 1 /3 innings split between Double-A and Triple-A, but he doesn’t have the stuff to be more than a back-of-the-rotation starter in the majors.

Exactly the same can be said of Maine, except that he’s had less recent success and more success in the past. Either could quite easily end up in Flushing as a swingman, and it would be no surprise if either ended up taking a few starts during the season. Paying attention to what they’re doing might allay some shock later in the year when you look out on the field and see a gaunt white guy throwing 89-mph fastballs.

A bigger mystery than any of these might be Michel Abreu, a 6-foot-3-inch, 230-pound first baseman who led Cuba in home runs four years running before defecting. Cuban position players haven’t generally proven all that impressive over the last few years, but on a bench a bit light on pop, Abreu could fill a useful role. And who knows? He, like Soler, or like any of these guys, could be more. It takes more than $13 million men to make a team.

tmarchman@nysun.com