On the June 7, 2010 episode of Raw, Cena was suddenly thrust into a new storyline when during his main event match against CM Punk, he was attacked by all eight former contestants of WWE NXT Season 1, with Wade Barrett as their leader. Punk, his follower Luke Gallows, and other personnel around the ring were attacked as well, but Cena took the worst of the attack and was carried out on a stretcher. This group would later refer to themselves as The Nexus. At Fatal 4-Way, Cena would go on to lose the WWE Title to Sheamus, in a fatal four-way matchup involving Edge and Randy Orton, after the Nexus would interfere. Cena would again lose to Sheamus, in a steel cage match, at Money in the Bank after the Nexus would once again interfere. Cena would, in retaliation to the Nexus, form an alliance with Edge, Chris Jericho, John Morrison, R-Truth, The Great Khali and Bret Hart to face the Nexus at SummerSlam, where Cena's team defeated Nexus with the returning Daniel Bryan, a former member of Nexus, who replaced Khali after getting injured.
Cena being forced to read a public address by Wade Barrett while a member of Nexus.
Hoping to end the Nexus, Cena would challenge Wade Barrett to a match at Hell in a Cell with the stipulations that if he were to lose, he would join the Nexus. After Barrett would defeat Cena, he would join the Nexus, and be forced by the Raw GM to follow their orders to avoid his contract getting terminated. Cena and fellow Nexus member, David Otunga, would defeat "Dashing" Cody Rhodes and Drew McIntyre to win the Tag Team Championship at Bragging Rights. Later on, Cena would be forced to help Barrett defeat Orton in a championship match, with Cena would do by giving Barrett the disqualification win. The following day, Cena and Otunga lost the Tag Team Championship to fellow Nexus members Heath Slater and Justin Gabriel, when Barrett ordered Otunga to lay down and lose the title. At Survivor Series, Cena officiated a match for the WWE Championship between Wade Barrett and Randy Orton. As a part of a pre-match stipulation, if Barrett didn't win the championship, Cena would be fired from the WWE.
Orton defeated Barrett to retain the title, thus terminating Cena's WWE contract. The following day on Raw, Cena gave a farewell speech, before costing Wade Barrett the WWE Championship by interfering in his rematch with Randy Orton. A week later, Cena invaded Raw, first as a spectator, but he then attacked members of Nexus, explaining that he would still take down Nexus one by one, despite not having a job in the WWE anymore. On the December 13 episode of Raw, Cena was rehired by Barrett, in exchange that he would face him at TLC: Tables, Ladders & Chairs in a Chairs Match. Prior to TLC, Cena teamed up with Randy Orton and Rey Mysterio to defeat Wade Barrett, The Miz and Alberto Del Rio at The WWE Tribute to the Troops. On December 19 at TLC: Tables, Ladders & Chairs, John Cena was victorious against Wade Barrett in a Chairs match in the main event of the evening.
John Cena at WWE Tribute to the Troops in 2010.
On the December 27 episode of Raw, The Nexus, minus Wade Barrett, announced they were under new management and offered to bury the hatchet with John Cena, to which Cena refused. The Nexus attacked Cena, leaving a Nexus armband in the ring during the process. As the group retreated, CM Punk, who had attacked Cena with a steel chair twice the week before, came to the ring to, what looked like attack John Cena, but instead put on the armband left behind to symbolically announce his allegiance with The Nexus. The next week, Wade Barrett returned to Raw and confronted CM Punk over the issue of who the leader of The Nexus was and who was responsible for Cena's attack the week before.