If a contender trades for a pitcher who is no younger than 36 and possibly several years older, whose ERA is 6.11, and who started a grand total of 37 games between 2003 and 2005, is it a big deal?

Count me a skeptic. Orlando Hernandez is one of my very favorite ballplayers of all time, a true legend in his own time, and nothing he does will surprise me. But he’s old and not what he once was, and the price of acquiring him was steep.

To give you the news, the Mets announced before last night’s game against the Phillies that they had acquired El Duque from the Arizona Diamonbacks in exchange for maligned reliever Jorge Julio. Hernandez, who made his name by pitching well in huge situations for the Yankees during the late 1990s, is 2-4 with a 6.11 ERA in nine appearances for Arizona this season.

“We’re happy to have El Duque,” general manager Omar Minaya told the Associated Press. “We needed starting pitching. The thing I liked a lot is he has pitched in New York. He’s happy to be coming back to New York, a place he knows and a place that knows him.”

First, to look on the positive side, the Mets simply need a starter capable of taking the ball every fifth day and keeping them in the game for five innings, and there’s no real reason to think El Duque isn’t capable of that. As anyone who’s watched him pitch a fair amount knows, his main problem when healthy is the long ball, and pitching in Arizona’s homer-inflating yard hasn’t helped him with that this year. In 28 2/3 home innings this season, he’s given up six gopherballs, leading to an unsightly 8.16 ERA; in 17 road innings he’s yielded just two home runs, and in those innings his ERA is 2.65.

Last year with the White Sox, Hernandez showed a similar pattern. In Chicago’s U.S. Cellular Field, a good home run park, his ERA was more than a run and a half higher than it was on the road. Pitching his home games in spacious Shea will give him his best chance to be effective because he’ll be able to throw his changeup in on the hands of lefties without worrying that it will fly out of the yard on contact.

Hernandez also may be able to help fellow Cuban Alay Soler, who made his major league debut last night, adjust to the major leagues – though there’s no guarantee of that. Shared nationality does not necessarily equate affinity. Plus, the help El Duque gave fellow exile Jose Contreras in Chicago last year was quite specific and based on videotapes he had of the delivery Contreras used in Cuba, rather than being vague and mystical. Still, if there’s a chance the old man can help Soler become a quality major leaguer, it’s a point in his favor.

On the negative side, Hernandez is, for all anyone knows, deep into his 40s, and he simply hasn’t been able to stay consistently healthy. As a deadly weapon against right-handed hitters and occasional starter, Hernandez is doubtless an asset for the Mets, especially given his unbelievable record of postseason success, which means Willie Randolph can have confidence giving him the ball should the Mets reach October.

But given that the Mets’ real need is for a starter who will take his turn in the rotation without embarrassing himself, this trade doesn’t leave the Mets much better off than they were before. It’s easy to imagine some sort of minor injury to El Duque leaving the Mets as reliant on Jeremi Gonzalez and his ilk as they were last week.

Further, Julio is a player of real value. After his disastrous first four appearances, in which he gave up seven runs in 3 2/3 innings, Julio suddenly became as dominant a relief pitcher as we’ve ever seen in New York. In 17 2/3 innings he struck out 27 batters and allowed only four runs, for a tidy 2.03 ERA. That he was only the fourth-best pitcher in the Mets’ pen doesn’t mean that he isn’t incredibly valuable – on a team with pitching issues like those the Mets have, being able to run out a reasonable approximation of vintage Armando Benitez (for better and for worse) in the fifth or sixth innings was enormously valuable, and an overtaxed pen will now be stretched all that much more thin.

There’s no easy answer on whether this was a good trade. It will depend entirely on results. If El Duque can run off a solid string of five-inning, three run starts with an occasional gem and serve ably in important games late in the season and perhaps even October, then the gamble will have paid off no matter what Julio does from here on out. If he can’t do that, it will have been a bad trade. The important thing for the Mets in the intermediate term is that this gives them a bit of breathing space, gives Omar Minaya a bit more leverage in negotiations for a more reliable starter, and gives the team a decent chance of having a top grade starter in the back of the rotation, at least for a few weeks. That’ not great. It’s not bad, either.

tmarchman@nysun.com