Symons has had an unorthodox route into the professional game. He started out in the Saracens youth side, being axed from the Academy system at 17 years old.
He was selected onto the Olympic Rowing Fast-Track programme, moving to Reading to train full time. After three years of intense training, injury forced him to retire in 2010 after unsuccessful surgery on his forearms.
After completing his university studies, while playing part time for Esher, Symons headed to Christchurch, New Zealand in 2012. Combining full-time work with the Earthquake Commission, and club rugby commitments in Christchurch.
He caught the eye of Scott ‘Razor’ Robertson, Crusaders Head Coach (The most successful rugby side in the Southern Hemisphere). Scott invited him to train with the squad, and he never looked back, going on to win a 2013 National Championship with Canterbury.
Due to his performances, he earned himself a Super Rugby contract with two-time champions the Chiefs for the 2014 Super Rugby season. Symons co-captained the side in his second season, alongside All Blacks Liam Messam and Aaron Cruden and earning the honour of being the first Englishman to ever captain a New Zealand Super Rugby team.
In 2015, Symons returned to the UK, signing for London Irish. It was an incredibly tough year for the club, and they were relegated from the Premiership. Despite this, Symons proved himself, and was voted Player of the Season.
Symons exercised his relegation clause with London Irish after their demotion to the Green King IPA Championship, signing for former London rival Wasps. A regular starter, he helped them to the Premiership Final in 2017, losing in extra-time to Exeter Chiefs in an enthralling match.
The 2018 season saw Symons pick up his first long term injury, having a plate inserted into his foot. He played on for a number of weeks after the initial injury, but was forced to have surgery, missing 7 months of the season.
Symons announced his return to London in 2018, signing a two-year deal with Harlequins. Back to full fitness, he has helped Harlequins to return to the top echelons of English club rugby.