We told you so.

From this corner of cyberspace, we’ve insisted that Cardinals general manager John Mozeliak really WAS willing to upgrade his team.

We assured you that Bill DeWitt really WOULD open up his vault and spend more money when the right opportunity arose.

They weren’t complacent with their team sitting atop the National League Central. Mozeliak wasn’t hapless and DeWitt wasn’t cheap.

Like other general managers and owners, they were waiting for the marketplace to open up. They were waiting for also-ran teams to actually make players available.

Saturday night, they struck. The Cards sacrificed Chris Perez, one of their blue-chip prospects – one of the Faberge eggs, as they like to say in the STLToday forums – to pry infielder/outfielder Mark DeRosa away from the Indians.

This was the No. 1 trade target for the Cards. This was the one available player capable of having the biggest and most immediate impact.

The Cards will miss Perez, who could become a long-run closer in the majors. They must also yield a “player to be named later” – still another strong prospect, we would suspect.

But the move had to happen. De Rosa can fill the immediate void at third base. He adds heft to the batting order, since he is hitting .270 with 13 homers and 50 RBI.

He bats from the right side, which is critical for this left-leaning team. While he isn’t the “impact bat” capable of “protecting Albert Pujols,” he is an established offensive threat capable of playing wherever the team needs him.

Last year he hit .285 for the Cubs with 30 doubles, three triples, 21 homers and 87 RBI. The year before that, he batted .293 with 28 doubles, three triples, 10 homers and 72 RBI. The year before that he hit .296 with 40 doubles, two triples, 13 homers and 74 RBI.

DeRosa offers everything that Tony La Russa loves in a player. He is versatile and highly competitive. Just ask the Cubs how much he is missed up on the North Side.

They have Milton Bradley instead. We’re seeing how well that is working out for the Small Bears.

The Cards will want to lock up DeRosa with a contract extension, ala Kyle Lohse. And he will certainly listen to such an offer after competing in the playoff race as a Cardinal.

He isn’t Matt Holliday in his prime, but then who is? Not Holliday himself; Matt hasn’t hit a home run since June 5 and he has driven in just two runs since June 6.

(In this corner of cyberspace, we pointed to Holliday’s mediocre road production as a Rocky. His inability to produce runs outside Colorado doomed him to disappointment in Oakland. Maybe this season is just a statistical fluke, but it’s something to think about when the A’s demand a huge package of players in return for him.)

The inability of Ryan Ludwick, Chris Duncan and Rick Ankiel to produce runs with any consistency necessitated this move. Khalil Greene’s relapse added more urgency, too. Although the Cards are still tied for first place, that dreadful series at New York was the Last Straw.

Something had to be done. That Mozeliak made this happen sooner than later is huge for La Russa, huge for Pujols and huge for the team.

Players can’t sit back and whine about the lack of support from their GM and their owner. Players can’t use this as an excuse for their inconsistent play.

Management got them some help a full month before the trade deadline. The message to the clubhouse couldn’t be clearer: The organization IS committed to winning this season.

Mozeliak dealt from his most immediate surplus, right-handed relief. Sacrificing Perez was made possible by the steady work of Ryan Franklin as the closer (the Cards needed to extend him, ala Lohse), the development of Jason Motte, the return of Josh Kinney and ongoing development of Memphis closer Jess Todd.

We’ve promoted the concept of moving Kyle McClellan to the starting rotation, but he, too, becomes more important to the bullpen with Perez’s exit.

This was a timely and sensible deal, one that helps the team now without derailing the organization’s overall progress.

Further dealing could occur, as Mozeliak figures out what to do with Khalil Greene and the Ghost of Troy Glaus. The Cards could use another starting pitcher, given Todd Wellemeyer’s ongoing struggle and Brad Thompson’s thin resume.

This team may need more offense, too, if at least two of the veteran outfielders don’t start hitting to their full potential.

Mozeliak and DeWitt WILL make changes, as needed, and not rely entirely on internal organizational solutions. Fans can see that now, as can the manager, his superstar and his players.

Everybody can shift their focus to the field now, where it belongs.