Cust, who hit his 30th home run of the season Sunday, played in 60 games in the outfield for Oakland in 2007, and he's played in 83 games as an outfielder this season.
But with an eye toward 2009, the A's have been using him almost exclusively as a DH down the stretch -- he last started in the outfield on Sept. 4 -- while Ryan Sweeney, Travis Buck, Carlos Gonzalez, Aaron Cunningham and Rajai Davis have been sharing time beyond the infield's border.
"I don't really mind DHing," Cust said. "The main thing is you have to try not to drive yourself crazy between at-bats. When you're playing in the field, you have to go out and concentrate on something other than your last time up, but when you DH you have all kinds of time. You might go up to the clubhouse to try to stay loose, you might check out some video ...
"It's easy to overanalyze that last at-bat when you're a DH, and most of the time that's not a good thing."
Cust last week set the American League record for strikeouts in a season (188 through Sunday), and his batting average entering the Rangers series was .230. But he also led the AL in walks (105), and he led the A's in RBIs (72), on-base percentage (.372) and slugging (.464).
"I think people tend to focus too much on the strikeouts with Jack," A's manager Bob Geren said. "The bottom line is he's a productive hitter for us, and he has been since the day he got here."
With a 2008 salary of about a reported $410,000, Cust is the cheapest 30-homer man in the Majors, but he'll likely command a nice raise in arbitration -- if he gets there.
The A's could non-tender him, making him a free agent, or they could try to avoid arbitration with a preemptive signing.
Cust said he hasn't had any talks with the A's about his future with the club, but he's said on several occasions that he'd like to be back.
And if he is, he said, "I'll be ready to play defense. I went into last winter as a DH, too."