By Morris Phillips

Santiago Casilla literally fell off the mound at Petco Park in San Diego on Saturday night, the statistics over a half season plus are howling, and the fans have spoken, almost in unison.

The consensus? The Giants need change in their bullpen, starting with veteran closer Casilla.

And the response from the Giants’ brass? Not a peep… yet.

With the August 1 trade deadline approaching, and the team sporting baseball’s best record despite a rough weekend in San Diego, how is that?

Probably because the trade that’s nearly inevitable may be the biggest one Bobby Evans has consummated in his short tenure as the team’s general manager, and one of the biggest in the Brian Sabean era. Let’s just say some high-level, serious negotiating is about to commence.

Already, the smoke screens are up, with the Yankees saying publicly that they’re not interested in anyone the Giants have in their farm system. But here’s what we know: The Yankees are undeniably sellers in this year’s market, as they flounder around .500, and in fourth place in the AL East just ahead of this weekend’s meeting with the Giants in the Bronx. And even as they move closer to moving some high-profile talent, most notably relievers Andrew Miller and possibly, flamethrower Aroldis Chapman, they too aren’t eager to tip their hand.

But what the Yankees have, the Giants need. That’s readily apparent.

If these two teams do a deal the historical implications are huge. The Yankees with their five World Series titles since 1996 are the team of this most recent era of baseball, and they aren’t particularly interested in sharing that stage with either the Giants or the Red Sox, both next up with three Series titles each in that same span. Also Brian Cashman may have tenure and titles, but he doesn’t have the reputation within the baseball industry that Sabean has amassed by doing more with less.

Simply, the two most tenured GM’s  (for the purpose of this story labeling Sabean a GM emeritus) in the game aren’t necessarily comfortable trade partners, especially given that Sabean left the Yankees to take a bigger role with the Giants.

Clearly, the Giants have the ammunition to make a trade with the Yankees or anyone else. From top prospect Christian Arroyo to pitcher Tyler Beede, infielder Lucious Fox, and Single A pitcher Phil Bickford, the Giants are awash with prospects unlike they’ve been at any point since 2010. The Giants have seen their farm system grow in reputation by leaps with the major league success of homegrown stars Joe Panik, Brandon Crawford, Buster Posey, Madison Bumgarner and others. What just a few years ago was a minus, has clearly become a plus.

If not the Yankees, look for the Giants to entice the Pirates with Mark Melancon, or the Rays with Alex Colome. Jeremy Jeffress of Milwaukee could be another rising star the Giants attempt to acquire.

But whatever transpires, don’t expect to hear a lot before it actually happens. Even broadcaster Mike Krukow seemed to be following the company line when he spoke on KNBR, saying that as constituted, the Giants’ bullpen has one logical guy to be the closer, Casilla, someone who he says has proven that he has the mental toughness to get the job done. With so many buyers, and only so many quality relievers available, the Giants tipping their hand, or overplaying their desire to close a deal, could simply drive up the price.

Casilla’s five blown saves are the second most of any reliever in baseball, and the bullpen as a whole has already blown 18. As it stands, with the long absence of Sergio Romo, and the struggles of Josh Osich and Hunter Strickland, the Giants’ bullpen lacks defined roles. The arrival of a flame throwing closer could change all that, bumping Casilla and Romo back, and creating a more defined back end of the pen. Also, even as high as the Giants are on both Strickland and Osich, one of the two also could be moved if it brings back the desired leader of the bullpen.

The Giants see what everyone else sees going on in their bullpen, but unlike the fans and the pundits, they don’t have a say a word. They have to close a deal.