Arsenal Early career After beginning his youth career with Ridgeway Rovers, Yennaris joined the
Arsenal Academy in May 2001 at age seven. He began his career as a
forward and as he progressed through the ranks, he was moved back into a
central midfield position, before being moved to
full back. Injuries halted his progress in 2008 and the club were planning to release him just weeks before he signed a two-year scholarship deal in 2009. Yennaris signed his first professional contract in July 2010, Yennaris made two further substitute appearances before joining
League One club
Notts County on a youth
loan in March 2012. Signing until the end of the
2011–12 season, Yennaris was named in just two first team matchday squads during the
2012–13 and
2013–14 seasons, making one appearance. He was an unused substitute on three occasions and failed to make an appearance for the club. Yennaris departed Arsenal on 27 January 2014,
Brentford Injury struggles (2014–2015) On 27 January 2014, Yennaris transferred to League One club
Brentford and signed a year contract for an undisclosed fee. After returning to fitness, he made sporadic appearances through to the end of a successful season for the Bees, Though he made only eight appearances during the second half of the
2013–14 season, Yennaris received a League One runners-up medal after the final match of the season against
Stevenage. Yennaris made his first appearance of the
2014–15 season in a League Cup first round match versus
Dagenham & Redbridge on 12 August 2014, but lasted just 20 minutes before suffering a back injury. After recovering and then suffering a thigh injury in September, Yennaris had to wait until 3 January 2015 to make his second appearance of the season, which came in a 2–0 FA Cup third round defeat to
Brighton & Hove Albion, when he replaced
Alan Judge after 88 minutes. On 27 February 2015, Yennaris joined
League Two club
Wycombe Wanderers on a one-month loan, which was later extended until the end of the
2014–15 season. He showed his versatility, playing in central midfield, right back and
centre back for the team. He scored the first senior goal of his career in Wycombe's 3–2 final-day win over
Northampton Town, which confirmed a fourth-place finish and qualification for the
end-of-season playoffs. Yennaris' season ended with a
shootout defeat to
Southend United in the
playoff final. He returned to Brentford after the match, after making 17 appearances and scoring one goal for the Chairboys. Starting in central midfield, he was forced off with a dead leg after 53 minutes of the 4–0 defeat. After returning to fitness, injury to regular right back
Maxime Colin saw interim manager
Lee Carsley bring Yennaris back to the team in early October and he held onto his place through to late-December, A shortage of midfielders and injury to Maxime Colin saw Yennaris regain his place in the team in mid-February 2016, He signed a new three-year contract on 16 February and after over two years at the club without scoring a goal, Yennaris scored in wins over
Nottingham Forest and Bolton Wanderers in early April and finished the season with 33 appearances. Yennaris was fit enough for a place on the bench versus
Huddersfield Town on the opening day and after coming on for
Josh McEachran in the second half, he scored his third Brentford goal on 77 minutes, though the match was eventually lost 2–1. Yennaris scored his second goal of the season on 2 January 2017, He was the club's only ever-present player during the 2016–17 season (with 49 appearances) and scored six goals. On 9 June 2017, Yennaris signed a new four-year contract.
Latter years (2017–2019) Yennaris lost his starting central midfield place to new signing
Kamohelo Mokotjo early in the
2017–18 season, but regained it in mid-August 2017 after an injury to Josh McEachran and a personal issue suffered by
Ryan Woods. After Maxime Colin transferred out of the club and right backs
Henrik Dalsgaard and
Josh Clarke suffered injuries, Yennaris returned to the right back position in December 2017. With the departure of former captain
Harlee Dean and club captain
John Egan also out, Yennaris also assumed the temporary captaincy of the team. During five years at
Griffin Park, Yennaris made 157 appearances and scored 12 goals. He made 25 appearances and scored two goals during the
2019 season. Yennaris made just three appearances during the
2021 season (again affected by COVID-19) and in November 2021 he was forced to undergo two surgeries in
London on an "uncommon" ankle injury. He missed the entire
2022 season and underwent a third surgery in London in July 2022. By December 2022, Yennaris was undertaking outdoor training at the
Arsenal Training Centre and by March 2023, he had returned to fitness and signed a two-year contract extension. Two weeks shy of two years since his previous appearance for the club, Yennaris made his first appearance of the
2023 season as a substitute for
Zhang Xizhe after 76 minutes of a 3–1 defeat to
Qingdao Hainiu on 25 April 2023. He made 24 appearances and scored one goal during the 2024 season, Yennaris was released at the end of the 2024 season, when his contract expired. His first competitive match involvement came as an unused substitute in the victorious
2025 Chinese FA Super Cup squad. ==International career==