Frank Lampard put his truth in youth during Chelsea's 4-0 defeat to Manchester United and Jose Mourinho thinks he made an error.
Marcus Rashford scored twice as Manchester United eased past Chelsea, while Arsenal also made a winning start against Newcastle United.
Manchester United hammered Chelsea 4-0 on Sunday and Blues coach Frank Lampard believes his side were made to pay for silly errors.
A fast, furious Manchester United ripped up Frank Lampard's best-laid plans, giving him a brutal introduction to Premier League management.
Frank Lampard's managerial debut for Chelsea ended in a humbling 4-0 defeat, their biggest top-flight loss to Manchester United since 1965.
Manchester United may not have been completely fluent against Chelsea, but they still managed to thrash the Blues 4-0.
With their starting XI averaging an age of 24 years and 227 days, Manchester United's team is the youngest in the Premier League this week.
Hannibal Mejbri is to join Manchester United from Monaco in a deal worth a reported £9million once the transfer has been cleared by FIFA.
Manchester United and Chelsea begin their Premier League seasons at Old Trafford, with lots to digest from the team news.
Manchester City boss Pep Guardiola has enough talent at his disposal to field two title-contending teams, according to Jose Mourinho.