Abraham, Blues colleague Chilwell and Borussia Dortmund winger Sancho are all due to link up with the rest of Gareth Southgate's England squad on Monday at St George's Park ahead of a clash against Wales at Wembley on Thursday.
The Sun claim around 20 people attended the surprise party at Abraham's house in London, which goes against current government restrictions. The newspaper's decision to publish forcing the player to apologise for his friends, family and loved ones who wished to celebrate his birthday.
Abraham said: “I arrived home to find a small surprise gathering.
“Though I was totally unaware this was planned, I would like to wholeheartedly apologise for the naivety shown for the organisation and attending of this gathering.
“All I can do now is learn from it, apologise to everyone and ensure it never happens again."