Watkins, who has 20 appearances for England and was part of their contingent at Euro 2024, was not included in Thomas Tuchel's 35-man squad for the matches at Wembley after struggling in front of goal for long spells during the season.
Since the squad was announced, however, he has rediscovered his touch and netted four times in as many games, including scoring his 100th goal for Villa in their 4-0 win over Bologna in the Europa League on Thursday.
Asked how he could work his way back into the England team, the 30-year-old told TNT Sports: "Just keep scoring goals.
"That's all I can do. I was disappointed not to be in the previous squad, but yeah, I can understand his (Tuchel's) reasons for not picking me.
"I just have to do my talking on the pitch and keep performing well and then score as many as I can come the end of the season."
England will play warm-up matches against New Zealand and Costa Rica in June as part of preparations for the World Cup, which will be hosted by the United States, Canada and Mexico from June 11 to July 19.
They open their Group L campaign on June 17 against Croatia in Dallas before facing Ghana on June 23 and Panama four days later.