Holland has four saves this season and has not given up a hit in four scoreless innings. He has been an All-Star the last two years.
"I tried to pitch through it," Holland said. "The ability to recover each and every day as a reliever is important. For me at this point of the season it's smarter for me to go on the DL. I just didn't feel comfortable."
"It just didn't feel good and didn't get any better after I was done throwing," Holland said. "I'm pretty optimistic. I feel a lot better today, but I'm a little sore."
The Baltimore Orioles put second baseman Jonathan Schoop on the 15-day DL because of a sprained right knee.
Schoop said he was injured when he tripped over first base in Friday night's game at Boston.