Rodney has been roughed up this season, surrendering 15 earned runs in 14 1/3 innings pitched for a bloated 9.42 ERA. He's only made four appearances for Oakland this month, two of which came in lower-leverage situations and another during a 13-inning loss.
"Obviously, some performance comes into play," manager Bob Melvin said, according to Ben Ross of NBC Sports Bay Area. "I will say he's not used to pitching in a role like that. He's used to getting regular work and we weren't giving that to him, for some obvious reasons, but at some point in time, you have a guy like that who's basically a one-inning guy that's used to working late in games and he's not getting consistent work.
"It just makes sense to try something different."
The right-hander spent parts of two seasons in Oakland. He was acquired in a trade with the Minnesota Twins last year and authored a respectable 3.92 ERA in 22 games to help the Athletics reach the playoffs.
He's been jarringly inconsistent throughout his career. The 42-year-old has pitched for 10 different teams over 17 seasons, racking up 325 saves. His 913 appearances lead all active pitchers.
Rodney, whose resume contains three All-Star selections, is on the books for $5.25 million this year.
In a corresponding move, the A's promoted left-hander Wei-Chung Wang from Triple-A Las Vegas. Wang, who last pitched in the majors with the Milwaukee Brewers in 2017, put up a 3.75 ERA with 22 strikeouts and one save in 16 appearances for Las Vegas.