Marcus Rashford appeared to blame Manchester United's 'inconsistent environment' for his struggles to perform consistently at his best during his career.
Rashford left Man United in the summer on a season-long loan move to Barcelona, which can be made permanent.
The 27-year-old has enjoyed an impressive start to life with the Catalan giants, scoring three times and providing five assists in 10 appearances to date.
Rashford's form has kept him in Thomas Tuchel's England squad in the build-up to next summer's FIFA World Cup.
The forward was asked by ITV ahead of England's latest qualifier against Latvia on Tuesday about Tuchel's assessment that Rashford only needs consistency to take him to a world class level.