His poor form continued into 2010, resulting 66th in the PGA Tour money list. He dropped out of the top 50 in the world rankings for the first time since the early 90s. After returning from knee surgery, Singh started the 2011 season making five out of his first five cuts. In February, Singh was in contention to win his first PGA Tour Title since 2008 at the Waste Management Phoenix Open in Scottsdale, Arizona. Despite shooting a final round 66, Singh finished two shots behind Jason Dufner and eventual winner Mark Wilson. A couple weeks later, Singh was in contention again, this time at the Northern Trust Open at Riviera Country Club. However he came up short again, not helped by back-to-back bogeys on holes 12 and 13. He would eventually finish two shots back of the winner Aaron Baddeley, although he did secure second spot on his own. This early season form however was not enough to secure a spot at the opening World Golf Championship of the year, the WGC-Accenture Match Play Championship the following week. However, at number 10 in the 2011 FedEx Cup standings, it was just enough to secure a spot at the WGC-Cadillac Championship in March. On 6 June 2011, Singh missed his tee-time for the U.S. Open qualifying in Columbus, Ohio. At the time, this ended the longest active streak of consecutive majors played by a professional golfer, at 67. On 30 January 2013, Singh admitted to using deer-antler spray while not knowing that it is a banned substance. The PGA Tour later dropped its case against him. On 8 May 2013, Singh sued the PGA Tour for exposing him to public humiliation and ridicule during a 12-week investigation into his use of deer-antler spray. On 20 November 2018, the PGA Tour and Singh announced that the lawsuit had been settled. The PGA Tour confirmed that it does not believe that Singh intended to gain an unfair advantage over his fellow competitors in this matter. Other terms of the settlement were not announced. In 2016, he finished second at the Quicken Loans National, three strokes behind winner Billy Hurley III. In March 2019, Singh shot his way into the final group of the final round of the Honda Classic. Singh shot even-par to finish sixth, three strokes behind winner Keith Mitchell. At age 56, he nearly became the oldest winner in PGA Tour history. Singh played his first PGA Tour Champions event in 2013, finishing T6 at the Pacific Links Hawai'i Championship.