It appears the Boston Red Sox could've used Anderson Espinoza as a trade to chip to acquire a left-hander not named Drew Pomeranz.

The Oakland Athletics told the Red Sox they were willing to swap Rich Hill for Espinoza, according to ESPN's Buster Olney.

After the Red Sox declined to give up the potential pitching prodigy, Oakland made another offer that didn't include Espinoza, and Boston walked away altogether.

The Red Sox ended up trading Espinoza, anyway, but instead in a straight up deal with the San Diego Padres, with the biggest piece being the All-Star Pomeranz.

At 27 years old, Pomeranz came into his own in his first year with the Padres. Although he's 8-7, he owns a sparkling 2.47 ERA in 102 innings pitched.

Espinoza is only in his second year of professional baseball, but he's already slotted as the Padres' top prospect. Despite the fact that he's small in stature at 6-foot, 160-pounds, his fastball sits in the 94-97 mph range.

The top trade chip left on the market, Hill left his start Sunday against the Toronto Blue Jays after just five pitches because of a popped blister.

The 36-year-old is 9-3 with a 2.25 ERA in 76 innings this season.