A number of trade rumors surfaced after San Francisco Giants executive VP Brian Sabean was spotted at Citi Field last weekend watching the series between the New York Mets and Washington Nationals.

One of them was upgrading at the third base position, possibly by acquiring Daniel Murphy.

It's no secret the Giants are experiencing offensive woes, which have been exacerbated by the struggles of incumbent third baseman Casey McGehee, who is batting .178/.231/.260 with five runs scored, one home run and three RBIs in 22 games (78 plate appearances). His BABIP is also just .211 and he has 19.2 percent strikeout rate. While the Giants are hoping he bounces back, it's reasonable to believe he doesn't.

As a result, ESPN Insider Jim Bowden notes the Giants are "hunting for a long-term answer at third base" and suggests a number of possible trade candidates that could interest the club and that other teams might be willing to deal.

"Giants GM Brian Sabean and the team's scouting department are out looking for an upgrade for this season and beyond," Bowden adds. "They are not interested in the Brewers' Aramis Ramirez because they prefer a player they can control past this season. Instead, [Adrian] Beltre, Trevor Plouffe and Chris Johnson are possible trade targets."

The most interesting is obviously Beltre. Aside from the latest three-game sweep of the Houston Astros after general manager Jon Daniels called out the club for their losing and all-around poor play, the Rangers really have nothing looking good for them. They rank 20th in runs scored (109) and 16th in team ERA thanks to their awful bullpen. The starting rotation has been kept at bay with a 3.65 ERA, but their 7-12 record is indicative of their inability to pitch deep into games (148 innings pitched ranks 26th). Injuries to Yu Darvish, Derek Holland and Matt Harrison will greatly hinder them from making a run at the postseason.

"The likelihood of the Rangers turning things around are slim. Not impossible -- the Rangers likely have a better shot at October baseball than teams such as the Phillies or Diamondbacks -- but baseball isn't just about the present, and there comes a point when you have to fold your hand and play the next one," writes ESPN Insider Dan Szymborski.

Beltre would be a good place to start for Texas if things look bleak by June or July. The 36-year-old is owed $34 million over the next two seasons and there's no sense for the Rangers to keep an aging veteran owed that much money on board if they don't have a shot at contending. He would be a valuable asset for a club looking to contend.

San Francisco fits the bill here because they're in the competitive NL West and, despite their 14-14 record, have struggled mightily in a variety of areas - most notably with their offense (28th in runs scored). Bowden notes the Giants hope to use their minor league pitching depth as trade bait, which is certainly something that can help Texas, depending on how prospects Jake Thompson, Luke Jackson and Alex Gonzalez develop.

Getting rid of Beltre can also expedite the promotion of top prospect Joey Gallo.

If McGehee doesn't get his offense off the ground and Texas can't find a way to dig themselves out of the hole they've dug, look for this trade scenario to gain more traction.