OAKLAND -- Burke Badenhop, who went from the rotation to a long relief role, was placed on the 15-day disabled list on Sunday with right shoulder tendinitis.

The Marlins had been carrying 13 pitchers. Now they will go with 12.

Badenhop, on the DL retroactive to June 14, doesn't believe his ailment is serious. But to make sure, he is expected to undergo an MRI when the Marlins return to Miami after Sunday's game at Oakland. He has been playing catch, but he hasn't thrown off the mound since June 13.

Replacing Badenhop on the roster was outfielder Jai Miller (pronounced Jay), who was called up from Triple-A Albuquerque. But immediately after Sunday's 7-1 loss to the A's at McAfee Coliseum, Miller was optioned back to Albuquerque.

The Marlins are off on Monday, and on Tuesday, the club is planning on activating left fielder Josh Willingham.

Willingham has been on the disabled list with a lower back strain since May 2. He has been playing in rehab assignments with Double-A Carolina.

In 13 games, with eight starts, Badenhop has a 2-3 record with a 6.08 ERA. He's logged 47 1/3 innings.

"It's something that kind of showed up in Seattle," said Badenhop. "We've been monitoring it a little bit, playing catch and stuff."

The Marlins obtained Badenhop from the Tigers as part of the deal last December that sent Dontrelle Willis and Miguel Cabrera to Detroit.

Badenhop's last appearance was on June 13, when he worked 2 1/3 innings at Tampa Bay. The right-hander is eligible to be activated on June 28, when the Marlins are home against Arizona.

A fourth-round Draft pick in 2003, Miller got his first taste of the big leagues. He entered Sunday's game in the seventh inning as a defensive replacement in center field. He struck out in his lone at-bat.