Faced with a Tuesday deadline invoked by Johan Santana, the Twins ended months of speculation by agreeing to deal the two-time Cy Young award winner to the New York Mets for four prospects, according to persons with knowledge of the discussions.

Santana is expected to receive a six-year deal that would pay him about $130 million, sources said. The trade hinges on a 72-hour window that closes on Friday afternoon for the Mets and Santana to negotiate a deal that would entice Santana to waive the no-trade clause in his current contract.

The Twins have traded top players for prospects before -- Frank Viola in 1989 and Chuck Knoblauch in 1998 -- and each time the deal was followed by at least one losing season before a run of success.

The Twins this offseason have lost Torii Hunter to free agency and likely Santana to the Mets. But even amid that gloom, Twins fans are not without hope. The team is building a new stadium set to open in 2010 and last week signed regulars Justin Morneau and Michael Cuddyer to long-term contracts.

Former Twins first baseman Kent Hrbek, who watched teammate Viola leave in 1989 and played in the 1991 World Series with players brought in by that trade, shared that cautious optimism.

"It all depends on what happens with the pitching staff they have and how well they will perform,'' said former Twins star Kent Hrbek. "If they pitch their butts off and do well, everyone will be like: 'Who?'"

The Twins are a microcosm of the entire Minnesota sports scene. In recent years, the Wolves' Kevin Garnett and Vikings standouts Randy Moss and Daunte Culpepper have all exited.

The Mets have agreed to send to the Twins outfielder Carlos Gomez, 22, and righthanded pitchers Philip Humber, 25, Kevin Mulvey, 22, and Deolis Guerra, 18. Gomez played 58 games for the Mets last year, and could contend for the starting center field job that opened when Hunter signed with the Los Angeles Angels.

Twins officials declined to discuss the deal until Santana completes an agreement with the Mets.

"We hope to have some resolution to the whole thing soon, but we don't have anything else to say today,'' Twins GM Bill Smith said Tuesday night.

The Twins offered Santana a four-year deal worth $80 million, but it became evident to team officials that he wanted to pitch on a bigger stage, such as New York or Boston. Team officials had become resigned in recent weeks to losing Santana.

"That's all we heard about all winter is [Santana] was going to be gone and traded,'' said Twins pitching coach Rick Anderson. "At first you think about it all the time. You expect it's going to happen, and when it finally does, it's like it really hasn't hit you yet.''

The deadline

According to a person familiar with negotiations, Santana and his agent, Peter Greenberg, gave the Twins until the end of the day on Tuesday to get a deal done or Santana would invoke his no-trade clause and remain with the Twins through the 2008 season. If that had happened, he would have left the team as a free agent at the end of the season, and the Twins would have received only two draft picks as compensation. Greenberg did not return interview requests.

Faced with that ultimatum, the Twins late last week asked each of the three main suitors for Santana -- the Mets, Yankees, and Red Sox -- for its best offer.

The Mets offer included players deemed to have the greatest potential. The tradeoff: The two best prospects, Gomez and Guerra, might not be ready to help for a year or two.

Gomez has blinding speed and is excellent defensively, but the jury is still out on his bat. If he hits, he could become a star. He will be given a chance to win the center field job in spring training.

Guerra, who stands 6-foot-5, has huge potential and pitched in high Class A ball last season at age 18, which doesn't happen often.

Mulvey is considered a middle-of-the-rotation prospect with Humber more of a No. 4 or 5 starter.

"It's four prospects for sure,'' Cuddyer said. "None of them has really proven themselves, but then again they're all young, and they'll have a chance to prove themselves. Gomez will have a chance to prove himself in center field this year.''

With Santana's $13.25 million salary moving off the books, the Twins' 2008 payroll could hover around $50 million for the first time since 2003, when it was $55.6 million. Morneau, who agreed to a six-year, $80 million contract last week, would be the highest-paid Twin at $7.4 million. Team officials have not ruled out adding a veteran pitcher via free agency.

The proposed trade to the Mets ends a seven-year run in the Twin Cities for Santana, who went an astounding 93-44 with a 3.22 ERA, won AL Cy Young awards in 2004 and 2006 and had a huge hand in making the Twins a consistent winner.

Departure foreshadowed

The warning signs that Santana's days as a Twin were coming to an end began a year ago when he warned that the club should sign him to an extension then or the cost of keeping him was going to increase.

He made national news after the July 31 trade deadline when he criticized the front office for not doing more to keep the club competitive. At the end of the season, he announced that he was willing to waive his no-trade clause for the right deal.

Indications during the offseason were that Santana, who will make $13.25 million this season, wanted a record-breaking deal and that he wanted to pitch on the big stage.

He's close to getting what he wanted.

As for the Twins, team officials can only hope the deal works out as well as the two most recent cases where the club dispatched an All-Star for prospects.

Viola, a Cy Young award winner, was dealt to the Mets in 1989 for five young pitchers. Two of them -- Rick Aguilera and Kevin Tapani -- became key members of the 1991 World Series championship team.

In 1998, the Twins traded second baseman Knoblauch to the Yankees for four prospects. Cristian Guzman and Eric Milton became All-Stars, helping the Twins end a streak of eight straight losing seasons and win the AL Central Division three straight seasons from 2002 through 2004.

For Twins fans, that past invites a reason for optimism.

"I'm extremely sorry to see Johan go,'' said Minneapolis Mayor R.T. Rybak, a self-professed die-hard fan. "But I believe this is exactly what this incredible franchise needs to do to sign the players who are key to our future, like [Joe] Mauer and Morneau and Cuddyer, and build the pitching staff that has tremendous promise. I'm sad, but I think it's the right move considering the way baseball works."

Staff writers M.L. Smith and Joe Christensen contributed to this report.