Entering the season, the A's bullpen was supposed to be a team strength. Instead, through 19 games, it has been a glaring weakness.

Oakland's 'pen blew a four-run lead Sunday at Texas, allowing five earned in just two innings, as the Rangers rallied for a stunning 8-7 victory. It was the A's third loss of the season when leading after seven innings. To put that in perspective, Oakland lost just two such games all of last year.

The root of the problem has been two high-paid veteran relievers: Joakim Soria and Fernando Rodney. Soria took the loss Sunday, his second of the season, after allowing four earned runs while recording only a single out.

"That's Soria's job to do it," A's manager Bob Melvin told reporters after the game. "He's one of our main guys. He just had a rough day."

Soria was the A's biggest free-agent signing of the offseason, as the 34-year-old right-hander received a two-year contract worth $15 million. In his first nine appearances, though, he has allowed nine earned runs in just 7 1/3 innings for an 11.05 ERA.