College
Griffin was one of the highest rated and most decorated recruits ever at Oklahoma. As a freshman at Oklahoma, he averaged 14.7 points and 9.1 rebounds in 28.4 minutes per game and led the Sooners to a 23–12 record. He ranked ninth in scoring, fourth in rebounding and third in field goal percentage in the Big 12 Conference. In a game against the Kansas Jayhawks, he suffered a sprained medial collateral ligament (MCL) in his left knee five minutes into the Sooners game. Less than two months after injuring his left knee, he injured his right knee in a home victory against Texas A&M. The injury this time was torn cartilage, and he had arthroscopic surgery on March 2, 2008. He missed the following game, a victory over in-state rival Oklahoma State Cowboys, but was back on the court a week after the injury with 14 points and 8 rebounds in 28 minutes versus the Missouri Tigers, a win for the Sooners on their home floor. He was a first-team all-district pick by the USBWA and NABC, and was named to the Big 12 All-Rookie Team and to the first-team All-Big 12 selection by league coaches andAssociated Press. He became the first Sooner to make the conference All-Rookie team since Wayman Tisdale in 1983 for the Big Eight Conference. He was expected to be a lottery pick in the 2008 NBA Draft but decided to return to college for a second season to give himself time to mature physically and make Oklahoma a contender for the NCAA championship.In his sophomore season, the Sooners started out the season winning their first 12 games before falling to the Arkansas Razorbacks. In the third game of the season against the Davidson Wildcats, he scored 25 points and grabbed 21 rebounds, after which he scored 35 points and 21 rebounds against Gardner–Webb, becoming the first player in Big 12 history to record back-to-back games of at least 20 points and 20 rebounds.] This earned him three consecutive Big 12 player of the week honor and finished the season with a record-tying six player of the week honors. In a home victory against the Texas Tech Red Raiders, he set career bests for both points and rebounds with 40 points and 23 rebounds, becoming the only player in Big 12 history and the third player in the history of the University of Oklahoma men's basketball program to score 40 points and get 20 rebounds in the same game, joining Wayman Tisdale (61 points and 22 rebounds in 1983) and Alvan Adams (43 points and 25 rebounds in 1975).On February 21, he received a concussion in a loss to the Texas Longhorns, when he caught an inadvertent shot to the face from the open hand of Texas centerDexter Pittman. He sat out the second half during the Sooners loss with a bloody nose. It was the Sooners' first loss of their conference schedule for the season. After sitting out the next game, a loss to Kansas Jayhawks, he was cleared by the medical staff and returned a week later to get 20 points and 19 rebounds in a victory over the Texas Tech Red Raiders. Oklahoma finished second in the conference with a 13–3 record but fell short in the first game of the Big 12 Tournament to the Oklahoma State Cowboys. In the "Big Dance", Oklahoma was seeded No. 2 in the South Region with a 27–5 record.[47] In the second-round win over the Michigan Wolverines, he scored 33 points and grabbed 17 rebounds, just the second player in the 2000s (decade) with at least 30 points and 15 rebounds in the NCAA tournament. However, the Sooners lost to the North Carolina Tar Heels in the South Regional final.