Eyenga played the 2010 NBA Summer League for the Cleveland Cavaliers. After that, he officially signed a two-year contract with the Cavaliers on July 23, 2010. He signed for $2 million over two years, with years three and four being options. On November 18, Eyenga was sent to the Cavaliers' NBA Development League affiliate, the Erie BayHawks. On January 2, he was recalled by the Cavs and made his debut on the same day, against the Dallas Mavericks. He scored 4 points and grabbed 3 rebounds.
On March 15, 2012, Eyenga was traded along with Ramon Sessions to the Los Angeles Lakers for a protected first round pick in the 2012 NBA draft, Jason Kapono and Luke Walton.
On August 10, 2012, Eyenga was traded to the Orlando Magic.
On October 23, 2012, Eyenga was waived by the Orlando Magic. He was then drafted by the Texas Legends of the NBA D-League. On January 4, 2013, Eyenga was released by the Legends so he could sign in China. In February 2013, he re-joined the Legends after a month in China.
In October 2011 he signed to play for Joventut Badalona in Spain during the 2011 NBA lockout.
In January 2013, he signed with Shanxi Zhongyu of China. He left the same month and returned to America.
On July 25, 2013, Eyenga moved to Poland and signed with Stelmet Zielona Góra. On August 4, 2014, he signed a one-year deal with another Polish team Turów Zgorzelec. In September 2014, Eyenga has been waived by the club. On November 12, 2014, he signed a one season contract with the Italian Serie A team Pallacanestro Varese.
On July 10, 2015, he signed with champions of Italy, Dinamo Sassari for the 2015–16 season. On February 5, 2016, he left Dinamo Sassari, and signed with Auxilium CUS Torino for the rest of the season.
On August 16, 2016, Eyenga signed with Pallacanestro Varese for the 2016–17 season. On May 14, 2017, he signed with Spanish club Unicaja for the rest of the 2016–17 ACB season.
On July 23, 2017, Eyenga signed with Fuenlabrada for the 2017–18 ACB season.
Note: The EuroLeague is not the only competition in which the player participated for the team during the season. He also played in domestic competition, and regional competition if applicable.