In January 2018, Soler signed his third new contract with Valencia in little over a year, tying him to the club until 2021 and increasing his release clause to €80 million. He totalled 51 appearances in 2018–19, including 13 in his debut European season in the UEFA Champions League and Europa League; he scored in group-stage wins over BSC Young Boys and Manchester United in the former. He played seven games in the season's Copa del Rey as Valencia won their first honour for 11 years, and assisted Rodrigo's winner in the 2–1 final victory over FC Barcelona on 25 May 2019.