In July 2009, Guo attended LeBron James' Skills Academy in Akron, Ohio, while already part of the Liaoning Hunters organisation, impressing some observers with his ball handling, dynamism and court vision.

[5] Struggling with communication (he reportedly spoke no English whatsoever) he impressed scouts in practice with his dedication and skill but had a quiet game against Team USA, going 1 for 5 from the field and committing two turnovers.

[9] Liaoning were vindicated in their decision as he then enjoyed a breakthrough 2012–13 CBA season, starting at point with 34 minutes per game on average as the team finished with its best record in several years and qualified for the playoffs.

[17] He had 26 points (on 91.7% shooting from two) in the team's 16th consecutive win during the penultimate round against the Tianjin Gold Lions, thus guaranteeing the franchise a historic regular-season first place.

[20] In game 3 of the playoffs first round against the Zhejiang Golden Bulls, he had 15 points and a game-high 11 assists to help the Flying Leopards to a 127–111 win and a series sweep.

[21] Moving on to the semis against the Guangdong Southern Tigers, Guo had 20 points, 6 assists and 4 rebounds in a 105–96 game 4 win that took Liaoning to the finals where they would face the unheralded Sichuan Blue Whales.

[22] After losing game 3 of the series away in Chengdu on 16 March, Guo was heavily involved in a brawl opposing Sichuan fans with members of the Liaoning organisation.

[23] He then had 17 points, 7 rebounds, 5 steals and a single assist in a combative performance during game 5 that proved in vain as Sichuan won 94–91 to keep the series and the championship in Chengdu.

[29] At 16, he was a surprise inclusion with the senior Chinese national team at the 2010 FIBA World Championship, making him the youngest ever player to turn up for China.

[31] The Junior National Team captain was said to have been the leader of a player revolt to oust coach Fan Bin because of his abusive style in April 2011.

[34] In the same age group, Guo participated in the World Championship played in Latvia in June/July 2011, contributing team bests of 15 points and 2.8 assists per game over the tournament.

[37] Recalled to the senior side in April 2012,[37] the 18-year-old was the youngest basketball player at the 2012 Olympic Games where he was a peripheral figure, taking part in three out of the five Chinese losses for 3.3 points and 1 rebound on average.

[38] Eager to impress in the 2015 FIBA Asia Championship played at home, Guo shone, contributing 10.9 points (on 54.8% shooting), 4 assists and 3.2 rebounds per outing in making the tournament's All-Star Five.

[28] That was helped by his commanding display in the final against the Philippines, outplaying his counterpart and fellow All-Star Jayson Castro to lead his team in scoring 19 points and grabbing 6 rebounds.