The sequence occurred with 3:12 remaining in the third quarter of the Thunder's 115-87 win Thursday at Chesapeake Energy Arena in Oklahoma City. The Thunder were playing defense when the Suns turned the ball over.
Adams knocked the ball loose, before turning to pursue a steal. That's when he blindsided Ferguson, who was trying to stay with his man and racing into the paint. Ferguson immediately collided with Adams and fell to the floor, with his body going limp.
The Thunder big man and his teammates called for the medical staff to help Ferguson. The Thunder guard was eventually escorted off the court.
Oklahoma City announced on Friday that Ferguson sustained a concussion and is in the NBA's concussion protocol.
"The Oklahoma City Thunder announced today that guard Terrance Ferguson sustained a concussion at the 3:12 mark of the third quarter during last night's 115-87 victory versus the Phoenix Suns and he has been placed in the NBA's concussion protocol," the Thunder said in a team statement.
"Per the NBA's Concussion Policy, Ferguson will now begin the NBA-mandated Return-to-Participation Protocol. This process includes a series of steps designed to ensure an athlete exhibits symptom-free behavior before resuming basketball activities. There is no predetermined timetable to complete the protocol, as each injury and player is different and recovery time can vary in each case.
"In 50 games [12 starts] this season, Ferguson is averaging 3.0 points and 0.7 rebounds in 12.1 minutes."
Ferguson, 19, had two points in 10 minutes in Friday's win. Suns guard Devin Booker led all scorers with 30 points. Russell Westbrook led the Thunder with 27 points.