The 40-year-old Poulter has been suffering from arthritic problems in his right foot and missed his last two cuts on the PGA Tour. He has fallen to No. 85 in the world.
"I am obviously disappointed to be in this situation, especially during a Ryder Cup year," Poulter said Friday. "Right now, rest and rehab take priority in me returning to full strength later this season. I look forward to resuming a full schedule as soon as I am able."
Poulter has competed for Europe at the past five Ryder Cups, totaling 14 points and a 12-4-2 record.
Poulter sparked Europe's comeback win at Medinah in 2012. He birdied his last five holes in the final four-ball match to turn a loss into a point, and he closed an undefeated week with a singles victory as Europe rallied from a 10-6 deficit to win the Cup.
Poulter likely would need to rely on Europe captain Darren Clarke to select him as one of the wild-card picks for the 41st Ryder Cup at Hazeltine National Golf Club in Chaska, Minn., from Sept. 30-Oct. 2.