Walters made his AFL debut for Fremantle in Round 11 of the 2009 AFL season at Football Park against Port Adelaide, after Hayden Ballantyne was a late withdrawal due to injury. He kicked a goal in debut match, minutes before fellow debutant and Swan Districts teammate Clancee Pearce also kicked a goal. Prior to the start of the 2012 AFL season, Walters was suspended from training with Fremantle and sent back to train and play for Swan Districts due to a poor fitness level and being overweight. He improved his fitness and performed well for Swans, and was accepted back at Fremantle in April and returned to the AFL in July, in round 16 against Melbourne. He played in every game after returning, kicking 22 goals from 10 games. In late September 2012 Walters was re-signed for a further two years, until the end of the 2014 season. In 2013 Walters had his best season to date, kicking 46 goals From 21 games, was named in the initial All Australian 40-man squad and won his first Fremantle leading goal-kicker award. In 2015, he had another consistent goal-kicking season, which saw him kick 44 goals across 22 games, winning his second Fremantle leading goal-kicker award. In the 2017 season, his standout performance came in Round 15, at Domain stadium against St. Kilda, where he collected a team-high 32 disposals and kicked 6 goals. He was ruled out for the remainder of the season after injuring his Posterior Cruciate Ligament in his left knee, in Fremantle's loss to Hawthorne in Round 18. Despite being moved into the midfield towards the middle of the season, he finished the season with 22 goals from 17 games. In 2018, especially after the suspension and subsequent injury to Nat Fyfe, Walters spent increasing amounts of time in the midfield, where he finished the season averaging 19.8 disposals per game, his highest average in his career so far. He won Fremantle's leading goal-kicker award, his 4th for the club, kicking 22 goals from 18 games. He was a finalist for mark of the year, where he was nominated for his high-flying mark on Jeremy McGovern, against West Coast in Round 20. Walters started 2019 in blazing fashion, averaging career-high figures. In Round 10, he kicked a behind after the siren to give the Dockers a 1-point win over Brisbane at Optus stadium. The following week in the Round 11 clash with Collingwood at the MCG, Walters kicked a goal with 30 seconds remaining to give the Dockers a 4-point lead which ultimately won them the game. Arguably, his best performance came in Round 13 when Fremantle played Port Adelaide at Optus stadium. He kicked 6.1 and picked up 25 disposals in the 21-point victory, and was awarded the maximum 10 in the AFLCA votes for his performance.
