The attacking midfielder was named in the Under-20s group for the first time, after an impressive start to the 2025/26 campaign with the Reds.
However, he was one of three players promoted into manager Thomas Tuchel's senior session, as the Three Lions prepare for the Alzheimer's Society International against Wales on Thursday, at Wembley.
Lakyle Samuel and Harrison Murray-Campbell also linked up with the squad, in front of watching journalists at St George's Park.
Defender Samuel is on loan at Bromley from Manchester City, while Murray-Campbell is a Chelsea centre-back.
Lacey scored twice in United Under-21s' recent victory over Crystal Palace and is making good progress, with this call, no doubt, being a valuable part of his education.