Now he's ready to turn pro.
O'Bryant, who has been projected as a late first-round or second-round draft pick, announced Tuesday that he will bypass his senior season and make himself eligible for the NBA draft.
''I am a better player now than a year ago,'' O'Bryant said. ''My mid-range jumper is better. I pass out of the double team better. Now, I have to get ready for the draft. I have no idea where I'll be drafted. I have to get in better shape and work hard. That's it.''
O'Bryant averaged a career-high 15.4 points to go with 7.7 rebounds this season.
He has career averages of 12.7 points and 7.7 rebounds a game and has been named to the All-Southeastern Conference first team the past two years -- only the ninth Tigers player to receive the honor twice.
The only three-time All-SEC players from LSU are Bob Pettit (1952-54), Pete Maravich (1968-70) and Shaquille O'Neal (1990-92).
''I am excited for Johnny and his family for his future,'' LSU head coach Johnny Jones said. ''But, I would love to have him back. I understand how important it would have been for Johnny to be back.
''Johnny didn't go through the [NBA] evaluation process like last year,'' Jones added. ''The interest shown by the scouts who showed up for our games speaks volume of his game.''
O'Bryant ended his career at No. 31 on LSU's scoring list with 1,157 points and No. 20 on the school's rebounding list with 702. He is only the 14th Tigers player to finish with 1,000 points and 700 rebounds.
In O'Bryant's three seasons, LSU never reached the NCAA tournament. The Tigers made NIT appearances in O'Bryant's freshman and junior campaigns. The Tigers lost to Oregon in the first round in 2012 and to SMU in the second round of this year's tournament last week.
''I didn't accomplish everything I wanted to do here,'' O'Bryant said. ''Last year, I said I wanted to take this team to the NCAA tournament. I failed to do that. I took the team as far as I could.''
LSU could lose another underclassman to the NBA. Jones said freshman second-team All-SEC post player Jordan Mickey is still deciding if he will put his name in the NBA draft. Freshman forward Jarell Martin has indicated that he will return for his sophomore campaign.
The Tigers will lose three of the six players who averaged at least 20 minutes per game this season: O'Bryant and senior guards Shavon Coleman and Andre Stringer, but Jones has newcomers set to step in at those spots.
Odessa (Tex.) Junior College guard Josh Gray and guard Keith Hornsby, who sat out this past season after transferring from North Carolina-Asheville, are expected to assume the minutes logged by Coleman and Stringer.
LSU has signed two freshman post players -- Elbert Robinson from Garland, Texas, and Anthony Epps from Tioga -- to replace O'Bryant and, possibly, Mickey.
''Josh Gray has the ability to score,'' Jones said. ''He can create opportunities for other people which would be huge for us. Hornsby has size and is strong. He has the ability to score and defend. Hopefully, Elbert Robinson and Anthony Epps will fill the void left by Johnny O'Bryant.''