Whether it's due to being over-aggressive, a few bad days or something else, one thing has proven true about the Arizona Diamondbacks this season:

They stink against soft-throwing lefties.

Over the last week Arizona has faced Jamie Moyer, Bruce Chen and Chris Capuano, losing to all three, and looking bad while doing so.

Moyer, who is just a few months shy of having been on this earth for a half-century, held Arizona to just one run on six hits in 6.1 innings of work. He walked two and struck out five in the Rockies' 6-1 win.

Then, just a few days later, the well-traveled Chen (he's played for nine teams in his 13-year career) limited the D-backs to just two runs on eight hits in 6.1 innings of work. He walked two and struck out four, leading the Royals to a 7-3 win and the D-backs to more shame.

Then, to add insult to insult, the D-backs were held in check by Dodgers lefty Chris Capuano Monday night, as a pitcher who has not been relevant since 2005 (but has been good this year) allowed just one run on four hits in six innings of work. He walked one and struck out five as the Dodgers cruised to a 6-1 victory.

"They feed off guys being over-aggressive and guessing they're going to get a fastball and then they don't get it," veteran utility-man Willie Bloomquist said after the game Monday.

"They play with your mind, and that's what makes them good," he added. "So you just have to get an approach and stick with it, no matter what the count, no matter what the situation."

Bloomquist is one of the few D-backs who has been OK against the three, as he collected five hits over the three games. But the rest of the team has struggled, and if it was simply a question of changing the team's approach then you have to wonder why it hasn't happened yet.

"We're trying to do too much," catcher Miguel Montero said. "Probably seeing it too good and can't put the barrel on it."

On the season the D-backs are hitting just .248 against lefties compared to .249 against right-handers, so it's not like there is a huge discrepancy either way.

However, be it against guys like Moyer, Chen, Capuano or any other pitcher, the bats really need to get going soon, because the D-backs are already 10.5 games back of the NL West-leading Dodgers and slowly running out of time to turn their season around.