ARLINGTON, Texas – Terry Ryan watched teenage Justin Morneau hit balls into the upper deck of the Metrodome before the 1999 draft, and "I think we knew at that moment," the general manager said, "that we had something."

They did, for 15 years, 11 of them in the majors — a Home Run Derby champion, a four-time All-Star, a clubhouse statesman, and in 2006, the American League Most Valuable Player. But Saturday, judging that a couple of younger players might be worth more in the future than the final month of Morneau's services in a lost season, Ryan dealt one of the faces of the franchise to Pittsburgh.

"It's tough. I was around Justin a long time," Ryan said after dealing half of the Twins' signature M&M duo to the first-place Pirates for outfielder Alex Presley and a player to be named — which, according to an mlb.com report, is righthanded reliever Duke Welker. "It was emotional for everyone involved."

Even after three solid months of speculation about his future. Morneau's six-year, $80 million contract expires once the season does, and the Twins tacitly let it be known he was available for a price. They received no offers they liked before the July trading deadline, but when no team claimed Morneau on waivers three weeks ago, the Twins had until Saturday night to offer him to a postseason contender.

On Saturday morning, about 12 hours after Morneau's 221st and final home run as a Twin carried his team to an energizing 3-2 victory over the Rangers, the Pirates made an offer Ryan didn't turn down. And just like that, Morneau was on a plane to Pennsylvania, arriving at the ballpark in the sixth inning of Pittsburgh's 7-1 victory over St. Louis, a victory that gave the Pirates a one-game lead in the National League Central.

"You look up and see the stands full. I knew what the score was, I checked the score when I landed, and we were listening on the radio on the way in," Morneau told the Pittsburgh Post-Gazette. "To see the boys up big and to come into that situation against the team you're battling with for first place was pretty special. Something I'll probably never forget."

En route to Pittsburgh, he penned a thank-you note to Twins fans and distributed it to Twin Cities media outlets, expressing his pride in having played before them. "I am sorry that during my time here, we weren't able to achieve our ultimate goal of winning the World Series, but I will forever carry many wonderful memories of my time here," Morneau wrote. "I will always cherish every day I was lucky enough to play in front of you fans in a Minnesota uniform."

There were several days when he couldn't play, too; he missed the 2009 postseason because of a stress fracture in his lower back that caused him to sit out most of September. And in July 2010, while sliding into second base during a game in Toronto, he collided with Blue Jays infielder John McDonald and suffered a concussion that ended one of his most productive seasons and lingered for months.

Morneau has been healthy again this season, and was eager to sign a new contract with the Twins, who chose to wait. He has even mentioned returning to Minnesota when he becomes a free agent, though Ryan wouldn't address his future.

"We did this for a number of reasons," he said, and though he didn't elaborate on many of them, the benefits are understandable, particularly for a 58-75 team.

The Twins will save the roughly $2.2 million that Morneau will earn in September, and they open a month's worth of at-bats for younger players. They acquired some much-needed outfield depth and a potential leadoff hitter in Presley, and another live arm for the bullpen in Welker, a Class AAA closer. "We wouldn't have done this," Ryan said, "if we weren't pleased with what might come back."

And, though Morneau had made it clear he preferred to stay with the only organization he has ever played for, the Twins did it for him.

"He's going to get an opportunity to go to a ballclub that's in contention and in a playoff atmosphere," Ryan said of the Pirates, who are all but guaranteed their first postseason berth since 1992. "As things settle in, as he gets to Pittsburgh and people give him the ovation that he'll receive, I think he'll be excited."

The Pirates already are.

"I talked to [Pirates manager] Clint Hurdle, and they are really, really excited to have him," Twins manager Ron Gardenhire said. "I asked [Hurdle], 'How you doing today?' and he said, 'Much better as of two hours ago.' "

The Twins aren't better off for the short term, not without the third-leading home-run hitter in franchise history. Morneau, though prone to streakiness, led the Twins in home runs with 17 and in RBI with 74. They also lost a vacuum at first base, a player who saved countless errors by scooping errant throws. And they lost a strong, if mostly silent, leader in the clubhouse, a player who led by example.

"No doubt, he was our leader," Gardenhire said. "He was the one who set the table in there. When something needed to be said, Mornie always was always able to step up."

With the Pirates, Morneau will displace former Twins teammate Garrett Jones, who might move to the outfield to make room. He put on uniform No. 36 — the 33 he made so familiar in Minnesota has been retired by the Pirates in honor of Honus Wagner.

Presley will arrive in Arlington on Sunday; Welker has not been announced as part of the trade yet, presumably because he must first clear waivers.

Presley is 28, and has been in the majors with the Pirates, off and on, for four seasons. He is a career .261 hitter, with the ability to play all three outfield positions.

"He's a catalyst-type guy. He can run, he throws [well] enough, he can steal a base," Ryan said. "He probably shouldn't hit the ball in the air much, because he's not a power-oriented guy. He's an athlete."

Welker is a former second-round pick, a 6-foot-7 hard-throwing righthander who saved nine games at Class AAA Indianapolis this year while posting a 3.25 ERA.