Now 16, the exciting attacking talent is tied to Chertanovo Moscow and has had several 'internships' with United's academy over the past three years.
However, Sport-Express via Mundo Deportivo says Barca are now in contact and aiming to sign Pinyaev.
Barca intend to secure the teen to a contract before loaning him to Russian Premier League outfit Khimki.
With Chertanovo in Russia's Second Division, Pinyaev has played 30 games - making his first team debut at the age of 15 - and has a contract to 2022.
The attacking midfielder's history with United dates back to when he was 13 years of age, where he first spent time in England four years ago. He has since had monthly spells training with the club's academy leading up to 2020.
Primarily a left-sided winger, Pinyaev now boasts six caps with Russia U17 and has a contract with Chertanovo to 2022.
- updated May 18