After the three-month suspension of the Premier League due to the COVID-19 pandemic, Nelson often was Mikel Arteta's favoured attacking substitute. On 15 July 2020, Nelson scored his first Premier League goal, starting in a 2–1 win against Liverpool. Nelson was in the squad as Arsenal won their 14th FA Cup against Chelsea on 1 August 2020. On 29 August 2020, Nelson came on as a substitute, taking and scoring the first penalty in a shootout win against Liverpool in the Community Shield after the game ended 1–1.