MIAMI -- The Pirates this morning placed shortstop Jack Wilson on the 15-day disabled list, a first in his career, and promoted shortstop Brian Bixler from Class AAA Indianapolis.

Wilson's left calf was strained after a hard slide by the Atlanta Braves' Matt Diaz Thursday, and it swelled significantly after that. The injury might have healed in time for Wilson to return late this week but, with second baseman Freddy Sanchez day to day because of that nagging right shoulder, management determined it could not afford two iffy everyday middle infielders.

Wilson is eligible to return for the Pirates' series in Chicago that begins April 18.

"We just couldn't wait much longer," manager John Russell said. "With Freddy the way he is now, we just couldn't carry two. We need some guys we can get out in the field. Plus, this gives Jack a chance to come back completely healthy."

Bixler is expected to arrive at Dolphin Stadium by 12:30 p.m. today, roughly 40 minutes before the scheduled first pitch between the Pirates and Florida Marlins.

Russell said Bixler, the Pirates' top shortstop prospect who will be seeing his first major-league duty, will get the bulk of the playing time during Wilson's disabled-list time.

"We're not bringing him up here to sit him," he added.

Also, Jason Bay and Adam LaRoche, the Pirates' struggling Nos. 3-4 hitters, will not start today.

Bay had been scheduled to have the day off, anyway.

"It's going to look like I'm doing this because of how things have gone for him," Russell said. "That's not the case."

LaRoche was given the day off because he has some "tenderness" in his right thumb, Russell said.

"He's been cheating a little on his swing," Russell said. "He tried to fight through it."