Papanikolaou is also the first player in EuroLeague history to record 2.000 points, 1.000 rebounds, 400 assists, 300 three-pointers made, 200 steals and 100 blocks.

On 20 July 2013, Papanikolaou signed a four-year deal with Spanish League club FC Barcelona,[10] after Barcelona bought Papanikolaou out of his contract with Olympiacos, paying a transfer buyout fee of €1.5 million to Olympiacos, and giving Papanikolaou a contract worth €5.5 million net income, during the contract's first three years (the 4th optional year would be at an additional salary).

On July 16, 2012, his draft rights were acquired by the Portland Trail Blazers, via a trade that sent Raymond Felton to the Knicks.

[13] On 10 July 2013, Papanikolaou's rights were acquired by the Houston Rockets, via a trade that sent Thomas Robinson to the Trail Blazers.

[15] On 13 February 2015, he took part in the Rising Stars Challenge of the NBA All-Star Game; in spite of an injury-plagued rookie season, during which he averaged 4.2 points and 2.7 rebounds per game, while coming off the bench, the Rockets decided to pick up his team option for the 2015–16 season.

[16] On 20 July 2015, the Rockets traded Papanikolaou, Joey Dorsey, Nick Johnson, Pablo Prigioni, a 2016 first-round draft pick, and cash considerations to the Denver Nuggets, in exchange for Ty Lawson and a 2017 second-round draft pick.

[25] In August 2009, Papanikolaou made his debut with the senior men's Greek national basketball team, in a friendly game.

A smart off-ball player with speed and size, Papanikolaou can play the positions 2-4 comfortably.