The Pittsburgh Pirates placed outfielder day disabled list, retroactive to August 23, on Wednesday.
Ludiwck, who the team acquired from San Diego at the non-waiver trade deadline on July 31, is suffering from muscle spasms in his mid-back.
In his 21 games since coming to Pittsburgh, he is batting .262 with a home run and seven RBI.
Both of Pittsburgh's big acquisitions at or near the traded deadline are now on the DL as Derrek Lee, who the team got from Baltimore on July 30, has been on the DL retroactively since August 10 with a broken left wrist.
To take his spot on the roster, the team selected the contract of pitcher Aaron Thompson from Triple-A Indianapolis.