NEW YORK -- The injury that ended Jose Valentin's season has forced the Mets to acquire a player who seemingly makes them a better team than they were before Valentin broke his leg 10 days ago. The acquisition of veteran second baseman Luis Castillo on Monday bolsters the batting order, marginally upgrades the running game and significantly reinforces the defense.

At minimal personnel cost -- two Minor League players not yet on the big-league horizon to the Twins -- the Mets addressed several needs and, in the process, made themselves younger. The club may not have made a splash comparable to what the Braves are trying to make with the Rangers' Mark Teixeira, but importing Castillo fits well in almost every way.

So the Mets front office was in celebration mode, albeit low key, on Monday as the team traveled to Milwaukee -- without the injured and likely disabled-list bound Carlos Beltran -- for a three-game series that includes a start that might make Tom Glavine a 300-game winner. The Mets were uncertain about Beltran's DL assignment, though they were leaning in that direction, and whether Castillo would join them in time for the Tuesday night game against the Brewers. But they were quite sure he had made the most of the circumstances.

With the non-waiver trade deadline less than 24 hours away, the club indicated it still was looking to upgrade its bullpen, but it was quite comfortable that it had done as much as it could for the starting eight.

Castillo, 32 in September and nearly six years younger than Valentin, will stabilize the No. 2 spot in the order. He will become the 15th player to bat second for the Mets this season and will take more pitches than most of the other 14, affording Jose Reyes greater opportunity to steal, and Castillo will be as much of a baserunning threat as his two-hole predecessors.

Yet when general manager Omar Minaya spoke of Castillo's acquisition in a conference call on Monday, he spoke primarily of the defense of the three-time Gold Glove Award winner.

"We pride our team as being pitching and defense," Minaya said. "Castillo is one of the best second basemen in baseball."

Although the general manager acknowledged he couldn't compare Castillo's defensive prowess now to what it was three or four seasons ago, he said Castillo "turns the double play" and that the Mets "needed someone on the right of [Carlos] Delgado who covers some ground."

Minaya noted that the Mets have many pitchers who pitch to contact, so Castillo's range helps in that regard, as well.

A switch-hitter more productive against left-handed pitching, Castillo was batting .304 with 11 doubles, three triples and 18 RBIs in 349 at-bats -- all as a No. 2 hitter -- with the Twins. Castillo's batting average since the All-Star break is .296. His July average is .313.

He had walked 29 times, stolen merely nine bases and scored 54 runs 85 games.

A former league leader in steals, he had stolen an average of 19 bases in the last four years. The Twins are fourth in the American League in stolen bases with 85, 40 fewer than the Mets.

Castillo's on-base and slugging percentages are .356 and .352, respectively. The corresponding composite figures produced from the Mets' two-hole this season are .351 (fourth in the National League) and .448 (sixth). Playing home games on artificial surface, Castillo had merely 11 doubles and three triples.

But 10 of his 18 RBIs came in 32 at-bats with runners in scoring position and two out. The Mets have been particularly deficient in those situations this season.

Castillo had his 32-game hitting streak at Shea Stadium, the longest streak in the 44-year history of the ballpark, ended on June 18 this year. The streak began Sept. 2, 2001, and ran through Sept. 20, 2005. He batted .388 in 129 at-bats. His career numbers at Shea include a .293 average with five doubles, three triples, one home run and 17 RBIs in 229 at-bats.

Castillo becomes eligible for free agency after the season, but if he performs as the Mets anticipate, they would be likely to pursue re-signing him. Minaya indicated the club had been planning to weigh signing Castillo for 2008 before the need for a trade developed.

"Now we get a longer look," Minaya said. "We know how he played as an opposing player. Now we'll see how he plays for us."

Castillo's presence diminishes the chance of Valentin returning next season and severely reduces the playing time of Ruben Gotay, who had been acquitting himself rather well at second base and as a hitter before and after Valentin's injury.

Despite working diligently on his defense with coach Sandy Alomar, Gotay was not the defensive player the club wanted, nor was he nearly as battle-tested as Castillo, who has played in 20 postseason games -- 17 with the Marlins in 2003 and three with the Twins in 2005.

There was no indication who the Mets would remove from the big-league roster to accommodate Castillo. But with Gotay now a reserve, David Newhan is a possibility. Or the Mets club could assign Beltran to the disabled list and delay removing a player until his return. If the Mets want an outfielder other than Newhan on the big-league, either Chip Ambres or Ben Johnson could be promoted.

To acquire Castillo, the Mets moved two players to the Twins: 23-year-old catcher Drew Butera, whose father, Sal, played for five big-league teams, and athletic 23-year-old center fielder Dustin Martin, who saw some action during Spring Training.

Neither was considered a top prospect. Butera is a mostly defensive catcher; Martin is a left-handed hitter who batted .315 in his first 251 professional at-bats with Class A Brooklyn last year. He was batting .287 and Butera .258 in 363 and 182 respective at-bats with the Mets' most competitive Class A team, St. Lucie.

The Mets didn't contact the Twins about Castillo until after Valentin broke his leg. And the talks didn't become series, Minaya said, until Sunday. The Twins originally sought more highly regarded prospects, but the Mets declined. Minaya said he wasn't sure until the weekend -- when the Twins fell seven games behind in the American League Central and 6 1/2 games behind in the Wild Card standings -- that Castillo was available.