If it goes through, this Carlos Beltran-to-the-Giants trade is going to change the complexion of the rest of the 2011 season and postseason.

Last week, you may recall, I wrote a column saying the Phillies should part with some of their future in order to obtain Beltran. That’s just what the defending champion Giants reportedly did, trading away 21-year-old pitching prospect Zack Wheeler. Wheeler is five days younger than the Phillies’ prized Jarred Cosart, as well as more highly rated by Baseball America. (Beltran has a no-trade clause but is expected to approve the deal.)

The trade raises the temperature on Phillies general manager Ruben Amaro Jr. to do something before Sunday’s deadline. It also blasts holes in two of the rationales that were floating around for the last week.

Many media types and readers argued the Phillies shouldn’t help the Mets for the long term by taking on free-agent-to-be Beltran as a three-month rental. Well, now the Mets have Wheeler, who has every bit as much chance as developing into a legitimate ace as Cosart. And the Giants – the team that eliminated the offensively challenged Phillies in the NLCS last October – would be a much more balanced team.

Last year, the Giants chose not to make a major move, adding only the released Cody Ross and a couple of middle relievers around the trade deadline. That has been used to support the idea the Phillies don’t really need to do much. Well, that logic looks a little wobbly now that those very same Giants, looking to repeat as World Series champs, have won the Beltran sweepstakes.

Everyone agrees the Phillies are good enough to reach the postseason for the fifth straight year. The issue is whether they’ve learned from two consecutive years of being eliminated because their always streaky lineup goes ice-cold against bigtime pitching. Standing pat now won’t cost the Phillies the NL East title. But it may haunt them in a series against the Giants or Braves or Red Sox or Yankees.

There’s no shame in losing the NLCS or the World Series. But it would be a shame not to address an easily predicted problem now, when there are some options.

If it’s Game 6 of the NLCS and Domonic Brown drives in the winning run while Beltran struggles against the Phillies’ pitching staff, then standing pat will look brilliant. But if Beltran is part of a mob of Giants celebrating on the field at the Bank this October, this is the week that made that possible.

Whatever happens, it makes for a fascinating storyline.

Of course, Amaro can still add to the cast of characters this week.