By all forms of reason, baseball expansion and Phoenix would seem to be splendid battery mates: baseball of the future and the city of the future.

The projections for growth are astounding in the Valley of the Sun. Forecasts show the current metropolitan population of 1.7 million swelling to 2.9 million by the year 2000. These numbers are far too great, city officials say, for Arizona residents to settle for major league baseball as it comes to them today: with eight teams in spring training (Cubs, Giants, Brewers, A's, Angels, Padres, Indians and Mariners) and two teams on the season-long radio dial (Angels and Dodgers).

"Phoenix is growing so fast that it reminds me of Los Angeles 25 years ago," says Martin Stone, the real estate entrepreneur who owns the Phoenix Giants of the Class AAA Pacific Coast League and aspires to own a major league baseball franchise in Phoenix. "You can see that Phoenix has had the same growth pattern as L.A."

Phoenix has many selling points. Can there be a better-situated middle leg than Phoenix, for instance, for a National League road trip from southern California to Houston?

However, amidst the massive growth, Phoenix also has a major flaw: it does not have a stadium for major league baseball.

The stadium used by the AAA Giants seats fewer than 10,000. Although there is talk of expanding it into a 25,000-seat facility in which a major league team could play for several seasons before a domed stadium might be built, this still would not negate the fact that a summer evening in Phoenix often boils at 95 degrees.

"Last summer in late July and August our team played 15 straight games where not an inning was played in under 100 degrees," says Stone. "Also, because Phoenix has a fairly elderly population with a lot of retired people who are financially well off enough to go to a lot of games, they are still not well enough physically to sit out in Phoenix Stadium in 100-degree weather."

There is another problem for Phoenix. It is related to perception as much as anything. Over the last two years, the Colts, Eagles and Cardinals of the National Football League tippy-toed through the Arizona desert. All three considered relocating in Phoenix, where they would have played in 70,000-seat Sun Devil Stadium on the Arizona State campus. None of the teams came.

"We get accused of raiding NFL cities, but we haven't done that at all," says David Maurer, executive director of the Phoenix Metro Sports Foundation, a Chamber of Commerce group comprising civic leaders who promote the city's sports interests. "We sat here innocently and they all came to us."

The result of those teams' interest in Phoenix is that this city now seems more enamored with acquiring a NFL club than a major league baseball team. It's as if the NFL whetted the appetite of Phoenix, and while a major league baseball franchise would help, it wouldn't satiate the hunger.

At least, that's how the vibes feel. "You get those vibes only because it seemed more realistic that we would get a football team than a baseball team," says Ed Lynch, president of the Sports Foundation and one of the civic leaders who was directly involved with the city's talks with the NFL teams. "We've been to the altar three times in the last 12 months with the NFL. There were a lot of headlines and publicity. As far as baseball is concerned, there have been no promises for expansion or even for the relocation of an existing franchise."

Market studies in Phoenix are checking into the feasibility of a domed stadium. The estimated cost of a multipurpose domed stadium -- one that could be used for baseball and football -- is between $80 million and $100 million, according to a recently finished study. Phoenix Mayor Terry Goddard's Sports Advisory Committee has recommended a downtown stadium site that would require another $20 million or $30 illion for land acquisition.

Several crucial questions, all linked in a chain of uncertainty, arise in discussing Phoenix, major league baseball and a domed stadium.

First, why would major league baseball come to a city that doesn't have a stadium? Next, should the city build a dome in hopes of luring a baseball team, as Indianapolis did in luring the football Colts? (One Phoenix official noted that Indianapolis also uses the Hoosier Dome for civic events and conventions, whereas Phoenix just went to great expense to expand its civic center.)

Now let's suppose Phoenix does decide to build a dome. How does the city persuade taxpayers to pay for a dome without the guarantee that a team will move in? And, worst of all, what if the dome is built and no team is acquired?

Further market studies are being carried out to find the most effective way to pay for a domed stadium. One study concluded that as much as $65 million could be raised from selling luxury boxes and prime seating in a potential domed stadium. Another large chunk of money might be paid by private investors.

"You have to realize that public-opinion surveys are real big here," says Maurer of the Metro Sports Foundation. "And every single survey says that the taxpayers will absolutely not pay for a stadium. I think it's been made clear that if you suggest that the taxpayers pay for it, you'll be laughed at."

On the other hand, he says, "If Phoenix doesn't have a dome or a dome plan ready to go, we'll miss two big opportunities -- baseball expansion and football expansion. Although both leagues haven't said, 'We'll expand,' they have made it clear that they will within the next five years. If we miss that, we can probably forget the rest of the century."

Stone, who is based in New York, says that a group of 17 Phoenix businessmen owns 25 percent of the AAA Giants and he owns the remaining 75 percent. This group of minority partners includes Lynch, former NBA players Tom and Dick Van Arsdale, and Jerry Colangelo, general manager of the National Basketball Association's Phoenix Suns. Stone says he would like a similar partnership for a major league franchise and that such a combination would fulfill one of baseball Commissioner Peter Ueberroth's three criteria for expansion -- multiple ownership with local roots.

Stone says he even has the answer to the question: Which comes first, the dome or the team?

"Major league baseball should decide for itself which are the best cities to expand into and then say to those cities, 'We are prepared to select you if by X date you have the building satisifactory to play in,' And then they should say that 'by Y date, you must be committed to being able to play in that facility.' "

Lynch added, "Peter Ueberroth has indicated that major league baseball will select their markets, not on the basis of whether a facility is in place, but on market viability. We still intend to go ahead with complete planning of our dome in anticipation of both baseball and football. (But) I'm not so sure we'll put a spade into the ground until we have a franchise promised in either football or baseball."

It is difficult to gauge the level of baseball fan support in Phoenix. On the one hand, Lynch notes that a recent study done by a local research firm indicated that 1.6 million people would attend baseball in Phoenix. Perhaps, too, one could assume support since spring training games and college baseball games are well attended in Arizona and since the Phoenix Suns averaged 12,035 per game this year, above the NBA average of slightly more than 11,000.

Stone notes that the minor league Giants have not drawn well the last few years. He said that support from business and media has not been good, either. "But you have to understand, up until last year Phoenix (Giants) had had three straight last-place finishes," he says. "The team hadn't given Phoenix a competitive brand of baseball."

For Phoenix, there is one bottom line in viewing the pro sports future. Says Pat Manion, Mayor Goddard's liaison to the Sports Advisory Committee, "Clearly, we are one of the strongest markets in the country that does not have either a baseball or a football team."