As the trade deadline approached this month, the Chicago White Sox desperately needed to upgrade their bullpen. Their cumulative 4.17 FIP ranks second worst in the American League, and their 3.99 ERA ranks only marginally better.

GM Kenny Williams looked to perhaps the only self-identified “seller” on the current market, the Houston Astros, for help. The White Sox acquired right-hander Brett Myers for minor-league pitchers Matthew Heidenreich and Blair Walters, as well as a player to be named later.

Despite saving 19 games for the Astros to this point, Myers will not immediately step in as the White Sox’s closer. That role will continue to belong to rookie Addison Reed, which only makes sense, as Reed has a better FIP, better stuff, and misses far more bats.

Reports suggest Myers will transition into the set-up role behind Reed and provide veteran stability in a bullpen that features rookies such as Reed, Nate Jones, and Hector Santiago. In terms of a talent upgrade, though, the White Sox may not have acquired as much as they previously thought.

Here are the main cogs in Chicago’s bullpen, sorted by FIP:

This is not to suggest that Myers is unequivocally the fifth-best reliever for the White Sox. After all, Myers has only six meltdowns this season, while Matt Thornton has eleven. Instead, the above chart is meant to illustrate that the White Sox did not acquire a shutdown reliever who will transform the entire bullpen. His inability to miss bats has limited his success all season, and that trend could become even more pronounced in the less pitcher-friendly American League.

Overall, the White Sox received marginal value. It’s difficult to see them even gaining a full win from this move.

For a non-elite bullpen arm with only a half-season of control remaining, it’s only natural that the Astros did not acquire anything earth-shattering. Neither right-hander Matt Heidenreich nor left-hander Blair Walters cracked Marc Hulet’s Top 15 White Sox Prospects list prior to the season, while ESPN’s Keith Law wrote over the weekend that both “barely qualify as prospects.”

The biggest win for the Astros in this transaction was avoiding the $10 million vesting option that was poised to enact had Myers finished 16 more games prior to the end of the season. The White Sox should also avoid the vesting option, as Myers is not slated to close games in Chicago.

This type of trade has precedent, as well.

Last season, the New York Mets traded right-hander Francisco Rodriguez to the Milwaukee Brewers in order to avoid his bulky $17.5 million vesting option that would have triggered if he had finished 55 games. That vesting option negated the Mets negotiating leverage and were forced to settle for two non-prospects, right-hander Adrian Rosario and left-hander Daniel Herrera.

Within that context, the Houston Astros crafted a quality deal. Not only did they trade away an inferior pitcher to Francisco Rodriguez, they also acquired far more in prospects. Heidenreich and Walters may not profile as more than back-end starters at the big league level, but Adrian Rosario has walked more batters than he has struck out in Double-A and Daniel Herrera is a journeyman, who underwent Tommy John surgery this year. The Astros certainly acquired more talent than the Mets last year for a less-attractive asset, especially when considering the fact that the Astros will also net a player to be named later in the deal, though that piece is not expected to be significant.

Ultimately, this is a win-win trade. The White Sox improved their below-average bullpen without sacrificing anything significant, while the Astros acquired pitching depth for their improving farm system and avoided a $10 million vesting option. Add in the K-Rod trade for context, and the Astros come out looking even better.