With the Yankees in need of pitching help after Tuesday's extra-inning affair, right-hander Chris Leroux had his contract selected from Triple-A Scranton/Wilkes-Barre.
"We assume Kelly is going to at least be [out for] 10 days, so we make that move and go from there," Yankees manager Joe Girardi said.
Girardi said that the Yankees needed to place Johnson on the disabled list because first baseman Mark Teixeira is nursing a left lat strain; Teixeira could take light swings on Thursday and there is hope that he would return to the lineup on Friday.
"I think you see how he feels tomorrow, then you make a decision about what would be a target date," Girardi said.
Leroux has made 65 big league appearances over six seasons with the Marlins, Pirates and Yankees. He pitched twice for New York this season, allowing five runs in two innings (22.50 ERA). At Triple-A, Leroux was 2-2 with a 5.08 ERA in six starts.
It has been a rough season for Johnson, who was expected to provide the Yankees with versatility and power. He has played five different positions, seeing most of his time at the infield corners, but has batted just .219 with six home runs and 22 RBIs in 77 games.
To make room for Leroux on the 40-man roster, New York designated right-handed pitcher Bruce Billings for assignment.
Bryan Hoch is a reporter for MLB.com. Follow him on Twitter @bryanhoch and read his MLBlog, Bombers Beat. This story was not subject to the approval of Major League Baseball or its clubs.